FCC&IC TEST REPORT

Product Information

Applicant: SHENZHEN LOFREE CULTURE CO., LTD

Manufacturer: SHENZHEN LOFREE CULTURE CO., LTD

Address: 201-F4,F518 Idea Land, 1065 Bao Yuan Road, Shenzhen

Product Name: FLOW 2-84 Triple Mode Low-Profile Mechanical Keyboard

Trade Mark: LOFREE

Test Model: OE927

Additional Model(s): /

Test Specifications

Standard(s) Applied:

• FCC 47 CFR Part 15 Subpart C (Part 15.249)
• Canada RSS-Gen Issue 5 (2018-04)
• Canada RSS-Gen Amendment 1 (2019-03)
• Canada RSS-Gen Amendment 2 (2021-02)
• Canada RSS-210 Issue 11 (2024-06)

Date of Receipt: 2025.07.03

Date of Test: 2025.07.03-2025.08.12

Date of Issue: 2025.08.13

Test Result: Pass

Report Details

Report No.: AB25060089FW03

FCC ID: 2AC59-OE927

IC ID: 32474-OE927

Compiled by: Huaijie Li

Supervised by: Jay Liu

Approved by: Mic Cheng

General Information

1.1. General Description of EUT

Product Name: FLOW 2-84 Triple Mode Low-Profile Mechanical Keyboard

Trade Mark: LOFREE

Test Model: OE927

Hardware Version: OE927-VIA-V1

Software Version: 1

Power Supply: DC 3.7V by battery(3000mAh) or DC from USB Port

Test Sample(s) Number: AB25060089-01 (Engineer Sample)

Radio Specification Subject to this Report

1.2. Description of Support Equipment

1.3. Description of External I/O

1.4. General Description of Applied Standards

The tests were performed according to following standards:

• FCC Rules Part 15.249 - Frequency Hopping, Direct Spread Spectrum and Hybrid Systems that are in operation within the bands of 902-928 MHz, 2400-2483.5 MHz, and 5725-5850 MHz and 24.0-24.25 GHz.
• ANSI C63.10-2013 - American National Standard of Procedures for Compliance Testing of Unlicensed Wireless Devices.
• Canada RSS-210 Issue 11 (2024-06)-Licence-Exempt Radio Apparatus:Categoryl Equipment
• Canada RSS-Gen Issue 5 (2018-04)-General Requirements forCompliance of Radio Apparatus
• Canada RSS-Gen Amendment 1 (March 2019)- A minor amendment has been made to section 3.6 Related documents toadd a reference to Radio Standards Specification (RSS-HAC), Hearing AidCompatibility and Volume Control, which shall be used in conjunction withapplicable RsS(s).
• Canada RSS-Gen Amendment 2 (February 2021)-Radio Standards Procedure RSP-102, Special Authorization Procedure forTerminal, Radio, Broadcasting and Interference-Causing Equipment to beCertified, Registered or Deemed in Compliance With Technical EquipmentStandards,replaces section 2.9 of this document.

1.5. Description of Test Facility

The test facility is recognized, certified, or accredited by the following organizations:

• A2LA-Lab Certificate No.: 7514.01
• FCC Accredited Lab. Designation Number: CN1411, Test Firm Registration Number: 567066
• ISED Wireless Device Testing Laboratories Company Number: 33924, CAB identifier: CN0185

1.6. Measurement Uncertainty

Note: All measurement uncertainty values are shown with a coverage factor of k = 2 to indicate a 95 % level of confidence.

1.7. Environmental Conditions

During the measurement the environmental conditions were within the listed ranges:

• Normal Temperature: +15°C ~ +35°C
• Lative Humidity: 20% ~ 75%
• Air Pressure: 98KPa ~ 101KPa

1.8. Description of Test Modes

The EUT was tested under the following mode.

Where: RE<1G: Radiated Emission below 1GHz; RE≥1G: Radiated Emission above 1GHz; PLC: Power Line Conducted Emission; BW: 20db bandwidth

NOTE: No need to concern of Conducted Emission due to the EUT is powered by battery or USB port.

Following channel(s) was (were) selected for the test as listed below:

Channel List

Note: The more detailed channel, please refer to the product specifications.

Summary of Test Result

FCC 47 CFR Part 15 Subpart C (SECTION 15.249) &RSS-210 Test Cases

Measurement Instruments List

Test Equipment

Test Software

4. Radiated Emissions Measurement

4.1. Limit

Emissions radiated outside of the specified bands, shall be according to the general radiated limits in FCC 15.209 and IC RSS-210 as following:

According to §15.249(a) and IC RSS-210, the field strength of emissions from intentional radiators operated within these frequency bands shall comply with the following:

The emission limit in this paragraph is based on measurement instrumentation employing an average detector. The provisions in §15.35 for limiting peak emissions apply.

NOTE:

1. The lower limit shall apply at the transition frequencies.
2. Emission level (dBuV/m) = 20 log Emission level (uV/m).
3. As shown in 15.35(b), for frequencies above 1000MHz, the field strength limits are based on average detector, however, the peak field strength of any emission shall not exceed the maximum permitted average limits, specified above by more than 20dB under any condition of modulation.

4.2. Test Setup

Below 30MHz test setup: A loop antenna is placed 3m from the EUT, which is on a turntable. The RF test receiver is connected to the antenna. A ground plane is present.

Below 1GHz test setup: The EUT is placed on a turntable 0.8m above the ground plane. An antenna tower with a variable height antenna (1-4m) is placed 3m away. An RF test receiver (Spectrum Analyzer) is used.

Above 1GHz test setup: The EUT and support units are placed on a turntable 1.5m above the ground plane. An antenna tower with a variable height antenna (1-4m) is placed 3m away. An absorber is placed near the turntable. An RF test receiver (Spectrum Analyzer) is used.

4.3. Test Procedure

1. The EUT was placed on the top of a rotating table 1.5 meters (above 1GHz) and 0.8 meters (below 1GHz) above the ground at a 3 meters semi-anechoic chamber. The table was rotated 360 degrees to determine the position of the highest radiation.
2. The EUT was set 3 meters away from the interference-receiving antenna, which was mounted on the top of a variable-height antenna tower.
3. The antenna is a broadband antenna, and its height is varied from one meter to four meters above the ground to determine the maximum value of the field strength. Both horizontal and vertical polarizations of the antenna are set to make the measurement.
4. For each suspected emission, the EUT was arranged to its worst case and then the antenna was tuned to heights from 1 meter to 4 meters and the rotatable table was turned from 0 degrees to 360 degrees to find the maximum reading.
5. The test-receiver system was set to Peak Detect Function and Specified Bandwidth with Maximum Hold Mode.
6. For below 30MHz, a loop antenna with its vertical plane is place 3m from the EUT and rotated about its vertical axis for maximum response at each azimuth about the EUT. And the centre of the loop shall be 1m above the ground.
7. If the emission level of the EUT in peak mode was lower than the limit specified, then testing could be stopped and the peak values of the EUT would be reported. Otherwise the emissions would be re-tested one by one using peak, quasi-peak or average method as specified and then reported in a data sheet.

NOTE:

1. The resolution bandwidth and video bandwidth of test receiver/spectrum analyzer is 120kHz for Quasi-peak detection at frequency below 1GHz.
2. The resolution bandwidth of test receiver/spectrum analyzer is 1MHz and video bandwidth is 3MHz for Peak detection at frequency above 1GHz.
3. The resolution bandwidth of test receiver/spectrum analyzer is 1MHz and the video bandwidth is 10Hz for Average detection (AV) at frequency above 1GHz.
4. All modes of operation were investigated and the worst-case emissions are reported.
5. The testing of the EUT was performed on all 3 orthogonal axes; the worst-case test configuration was reported on the file test setup photo.

4.4. Test Result

Below 1GHz Worst-Case Data (30MHz to 1GHz)

Environmental Conditions: 24.6℃, 53.4% RH | Test Engineer: Jacey Fu

TX Low Channel - Horizontal Polarity

Remark: Emission Level = Reading + Factor; Factor = Antenna Factor + Cable Loss – Pre-amplifier; Margin= Limit - Emission Level. 9KHz~30MHz have been test and test data more than 20dB margin.

TX Low Channel - Vertical Polarity

Remark: Emission Level = Reading + Factor; Factor = Antenna Factor + Cable Loss – Pre-amplifier; Margin= Limit - Emission Level. 9KHz~30MHz have been test and test data more than 20dB margin.

TX Middle Channel - Horizontal Polarity

Remark: Emission Level = Reading + Factor; Factor = Antenna Factor + Cable Loss – Pre-amplifier; Margin= Limit - Emission Level. 9KHz~30MHz have been test and test data more than 20dB margin.

TX Middle Channel - Vertical Polarity

Remark: Emission Level = Reading + Factor; Factor = Antenna Factor + Cable Loss – Pre-amplifier; Margin= Limit - Emission Level. 9KHz~30MHz have been test and test data more than 20dB margin.

TX High Channel - Horizontal Polarity

Remark: Emission Level = Reading + Factor; Factor = Antenna Factor + Cable Loss – Pre-amplifier; Margin= Limit - Emission Level. 9KHz~30MHz have been test and test data more than 20dB margin.

TX High Channel - Vertical Polarity

Remark: Emission Level = Reading + Factor; Factor = Antenna Factor + Cable Loss – Pre-amplifier; Margin= Limit - Emission Level. 9KHz~30MHz have been test and test data more than 20dB margin.

Above 1GHz Worst-Case Data

Environmental Conditions: 24.6℃, 53.4% RH | Test Engineer: Jacey Fu

Lowest Channel (Worst Case: 2.4G_2404MHz)

Middle Channel (Worst Case: 2.4G_2438MHz)

Highest Channel (Worst Case: 2.4G_2476MHz)

Remark: Emission Level = Reading + Factor; Factor = Antenna Factor + Cable Loss – Pre-amplifier; Margin= Limit - Emission Level. " * ": Fundamental frequency. The emission levels of other frequencies were greater than 20dB margin. Testing is carried out with frequency rang 9kHz to the tenth harmonics. The measurements greater than 20dB below the limit from 18GHz to 25GHz.

Radiated Band Edges Test Data

Environmental Conditions: 24.6℃, 53.4% RH | Test Engineer: Jacey Fu

Lowest Channel (Worst Case: 2.4G_2404MHz)

Highest Channel (Worst Case: 2.4G_2476MHz)

Remark: Emission Level = Reading + Factor; Factor = Antenna Factor + Cable Loss – Pre-amplifier; Margin= Limit - Emission Level. The emission levels of other frequencies were greater than 20dB margin.

5. 20dB Bandwidth and Occupied Bandwidth

5.1. Limit

According to FCC 15.215(c) and RSS-Gen, must be designed to ensure that the 20 dB bandwidth of the emission, or whatever bandwidth may otherwise be specified in the specific rule section under which the equipment operates, is contained within the frequency band designated in the rule section under which the equipment is operated.

According to RSS-Gen 6.7, The occupied bandwidth shall be reported for all equipment in addition to the specified bandwidth required in the applicable RSS.

5.2. Test Setup

The EUT is connected to a spectrum analyzer through a 10dB attenuation pad.

5.3. Test Procedure

For 20dB Bandwidth Measurement:

1. Check the calibration of the measuring instrument using either an internal calibrator or a known signal from an external generator.
2. Turn on the EUT and connect it to measurement instrument. Then set it to any one convenient frequency within its operating range. Set a reference level on the measuring instrument equal to the highest peak value.
3. Measure the frequency difference of two frequencies that were attenuated 20dB from the reference level. Record the frequency difference as the emission bandwidth.
4. Repeat above procedures until all frequencies measured were complete.
5. The transmitter output was connected to the spectrum analyzer through an attenuator. The bandwidth of the fundamental frequency was measured by spectrum analyzer with 30 KHz RBW and 100 KHz VBW. The 20dB bandwidth is defined as the total spectrum the power of which is higher than peak power minus 20dB. Measured the 20dB bandwidth by related function of the spectrum analyzer.

For 99% Occupied Bandwidth Measurement:

1. Span = approximately 1.5 to 5 times the OBW, centered on the test channel.
2. RBW = 1% to 5% of the OBW.
3. VBW ≥ 3 x RBW
4. Sweep = auto;
5. Detector function = peak
6. Trace = max hold
7. Use the 99% power bandwidth function of the instrument to measure the Occupied Bandwidth and recoded.

5.4. Test Result

Test Data: Low channel

Spectrum analyzer screenshot shows the occupied bandwidth measurement for the low channel (2404 MHz). The occupied bandwidth is 2.0939 MHz, and the x dB bandwidth (20dB) is 2.309 MHz.

Test Data: Middle channel

Spectrum analyzer screenshot shows the occupied bandwidth measurement for the middle channel (2438 MHz). The occupied bandwidth is 2.1149 MHz, and the x dB bandwidth (20dB) is 2.370 MHz.

Test Data: High channel

Spectrum analyzer screenshot shows the occupied bandwidth measurement for the high channel (2476 MHz). The occupied bandwidth is 2.0969 MHz, and the x dB bandwidth (20dB) is 2.362 MHz.

6. Power Line Conducted Emissions

6.1. Limit

According to the rule FCC Part 15.207 and IC RSS-Gen 8.8, Conducted emissions limit, the limit for a wireless device as below:

Remark: a) The lower limit shall apply at the transition frequencies. b) The limit decreases linearly with the logarithm of the frequency in the range 0.15 to 0.50MHz.

6.2. Test Setup

The test setup involves a shielded room, an EMI Receiver, a Line Impedance Stabilization Network (LISN), and the EUT & Auxiliary Equipment. A vertical reference plane and a horizontal ground reference plane are used. The EUT is connected to AC power source through LISN 1. Other equipment is connected to LISN 2.

6.3. Test Procedure

Test frequency range: 150KHz-30MHz

1. The mains terminal disturbance voltage test was conducted in a shielded room.
2. The EUT was connected to AC power source through a LISN 1 (Line Impedance Stabilization Network) which provides a 50Ω/50μH + 5Ω linear impedance. The power cables of all other units of the EUT were connected to a second LISN 2, which was bonded to the ground reference plane in the same way as the LISN 1 for the unit being measured. A multiple socket outlet strip was used to connect multiple power cables to a single LISN provided the rating of the LISN was not exceeded.
3. The tabletop EUT was placed upon a non-metallic table 0.8m above the ground reference plane. And for floor-standing arrangement, the EUT was placed on the horizontal ground reference plane.
4. The test was performed with a vertical ground reference plane. The rear of the EUT shall be 0.4 m from the vertical ground reference plane. The vertical ground reference plane was bonded to the horizontal ground reference plane. The LISN 1 was placed 0.8 m from the boundary of the unit under test and bonded to a ground reference plane for LISNs mounted on top of the ground reference plane. This distance was between the closest points of the LISN 1 and the EUT. All other units of the EUT and associated equipment was at least 0.8 m from the LISN 2.
5. In order to find the maximum emission, the relative positions of equipment and all of the interface cables must be changed according to ANSI C63.10 on conducted measurement.

6.4. Test Result

Pass.

Remark: a) AC Power line conducted emissions pre-test both at AC 120V/60Hz and AC 240V/50Hz modes, recorded worst case. b) Worst-case mode and channel used for 150KHz~30MHz power line conducted emissions was determined to be 2.4G_2404MHz.

Test Plots and Data of Conducted Emissions (Worst Case: 2.4G_2404MHz)

Environmental Conditions: 24.6℃, 53.4% RH | Test Engineer: Jacey Fu

AC 120V/60Hz - Live Line

Remark: Emission Level = Reading + Correct Factor; Correct Factor = LISN Factor + Cable Loss + Pulse Limiter Attenuation Factor; Margin= Emission Level - Limit.

AC 120V/60Hz - Neutral Line

Remark: Emission Level = Reading + Correct Factor; Correct Factor = LISN Factor + Cable Loss + Pulse Limiter Attenuation Factor; Margin= Emission Level - Limit.

7. Photographs of Test Setup

Please refer to separated files for Test Setup Photos of the EUT.

8. External Photographs of the EUT

Please refer to separated files for External Photos of the EUT.

9. Internal Photographs of the EUT

Please refer to separated files for Internal Photos of the EUT.