1. Introduction
The Sofirn SK40 is a powerful and versatile tactical flashlight designed for various applications including hiking, camping, hunting, exploring, and fishing. It features a high-powered SFT70 LED, delivering up to 3200 lumens and a long-distance beam of up to 580 meters. Equipped with both a clicky tail switch and a side electronic switch, the SK40 offers dual operating modes (Duty and Tactical) to adapt to different user needs. Its robust construction and IP68 waterproof rating ensure reliable performance in challenging environments.
2. Setup
2.1 Battery Installation
The Sofirn SK40 uses one 21700 battery, which is included with the flashlight. To install the battery:
- Unscrew the tail cap of the flashlight.
- Insert the 21700 battery with the positive (+) end facing towards the head of the flashlight.
- Screw the tail cap back on securely.
2.2 Initial Charging
Before first use, it is recommended to fully charge the battery. The SK40 features a convenient USB Type-C charging port.
- Locate the USB Type-C port on the flashlight body.
- Connect the included USB charging cable to the flashlight's Type-C port.
- Connect the other end of the cable to a USB power adapter (not included) with a 5V/2A (max) output.
- The battery will be fully charged in approximately 3 hours.
3. Operation
The SK40 features a dual-switch design for convenient operation: a tail tactical switch and a side electronic switch. It offers two main modes: Duty Mode and Tactical Mode.
3.1 Switching Between Modes
Long press the side electronic switch from the ON position to switch between Duty Mode and Tactical Mode.
3.2 Duty Mode Operation
Duty Mode is suitable for general lighting needs.
- Tail Switch:
- 1 Click: Turns the flashlight ON/OFF.
- Half Press + Click: Activates Turbo mode momentarily. Release to turn off.
- Side Switch (from ON):
- 1 Click: Cycles through brightness levels: Low → Medium → High.
- 2 Clicks: Activates Turbo mode.
- 3 Clicks: Activates Strobe mode.
- 2 Clicks (from Strobe): Activates Beacon mode.
3.3 Tactical Mode Operation
Tactical Mode is designed for rapid response and specialized situations.
- Tail Switch:
- 1 Click: Turns the flashlight ON (Turbo mode) / OFF.
- Half Press + Click: Activates Strobe mode momentarily. Release to turn off.
- Side Switch (from ON):
- 1 Click: Cycles through brightness levels: Turbo → Medium.
- 2 Clicks: Activates SOS mode.
- 2 Clicks (from SOS): Activates Beacon mode.
4. Charging & Battery Indicator
4.1 Battery Level Indicator
After turning on the SK40, the side indicator light will display the battery voltage for 5 seconds:
- Green Constant On: 70%-100% battery remaining.
- Red Constant On: 30%-70% battery remaining.
- Red Flash: 0-30% battery remaining.
4.2 Charging Indicator
When the flashlight is connected for charging:
- Red: Charging in progress.
- Green: Battery is fully charged.
5. Maintenance
- Cleaning: Regularly clean the flashlight body with a soft cloth. If the threads are dirty, clean them with a clean cloth and apply a thin layer of silicone grease.
- Water Resistance: The SK40 is IP68 waterproof, meaning it is protected against continuous immersion in water up to 2 meters. Ensure all seals are intact and properly seated before exposing to water.
- Temperature Protection: The flashlight features a temperature protection system that automatically reduces output if the temperature exceeds 55°C to maintain optimal performance and prevent overheating.
- Reverse Polarity Protection: The device includes reverse polarity protection to prevent damage from improper battery installation.
- Storage: If the flashlight will not be used for an extended period, remove the battery to prevent potential leakage and damage.
6. Troubleshooting
- Flashlight not turning on:
Ensure the battery is correctly installed with the positive end facing the head. Check if the battery is charged. Try cleaning the battery contacts and threads. - Light is dim or flickers:
The battery may be low; recharge it. Ensure the battery is fully seated and contacts are clean. - Charging issues:
Verify the USB cable is securely connected to both the flashlight and the power adapter. Ensure the power adapter provides 5V/2A (max) output. Check the charging indicator light for status.
7. Specifications
| Feature | Detail |
|---|---|
| Emitter | 1 high-powered good thrower LED (SFT70) |
| Driver | Boost driver |
| Battery Option | 1 × 21700 battery (included) |
| Working Voltage | 3.0V-4.2V |
| Mode Operation | Side e-switch + Tail switch |
| Charging | USB Type-C (5V/2A max input/output) |
| Body Material | AL6061-T6 aluminium alloy |
| Water Resistance | IP68 waterproof |
| Size | 40mm (head diameter) × 146.5mm (length) |
| Weight | 132g (without battery) |
| Lighting Distance | > 500 meters |
| Wattage | 30W |
| Certification | CCC, CE, FCC, ROHS |
| Switch Mode | High/Middle/Low |
| Support Dimmer | 5 - 8 Files |
| Focal Length | Non-adjustable |
| Flashlight Type | Hiking, camping, hunting, exploring, fishing |
| Characteristic (feature) | Spotlighting and long-distance shooting |
| Impact Resistance | 1m / 3.28 ft. |
8. User Tips
- Battery Included: The SK40 flashlight comes with a battery included, so you can use it right out of the box after an initial charge.
- Familiarize with Modes: Take time to understand both Duty and Tactical modes and their respective switch operations to quickly access the desired light output in any situation.
- Regular Charging: For optimal performance and battery longevity, ensure the battery is regularly charged, especially before extended use.
9. Warranty & Support
For warranty information or technical support, please refer to the official Sofirn website or contact your point of purchase. Keep your proof of purchase for any warranty claims.