1. Safety Information
Please read these instructions carefully before using the device. Failure to follow safety guidelines may result in injury or damage to the product.
- Do not use the device near heat sources or open flames.
- Do not expose the device to rain or water.
- Keep the device out of reach of children and pets.
- Do not disassemble or modify the product.
- In case of doubt regarding operation or safety, consult a professional.
2. Product Overview
The FOLAI TH550 is a versatile 5-in-1 wall detector designed to accurately locate various hidden elements behind walls, floors, and ceilings. It identifies metal pipes, live AC wires, wooden studs, rebar, and other support beams, enhancing safety during drilling or construction tasks.

Image: The FOLAI TH550 Wall Detector features an intelligent microprocessor chip for precise and reliable detection of hidden objects.
3. Package Contents
Verify that all items are present in the package:
- 1 x FOLAI TH550 Wall Scanner Detector
- 1 x 9V Battery
- 1 x User Manual
4. Specifications
| Brand | FOLAI |
| Model Number | TH550 |
| Material | Plastic |
| Power Source | 9V Battery (included) |
| Display Type | LCD |
| Recommended Use | Structure Detection |
| Stud Scan Depth | 0.5 inch (12mm), 1 inch (25mm), 1.5 inch (38mm) |
| AC Scan Depth | 2 inch (51mm) |
| Metal Scan Depth | 2.36 inch (60mm) |

Image: The detector offers five scan modes with varying detection depths for studs, AC wires, and metal.
5. Setup
5.1 Battery Installation
- Open the battery compartment cover located on the back of the device.
- Insert the included 9V battery, ensuring correct polarity (+ and - terminals).
- Close the battery compartment cover securely.
5.2 Initial Power On
Press the ON/OFF button to power on the device. The LCD screen will illuminate.

Image: Front view of the FOLAI TH550 Wall Detector, displaying its LCD screen and control buttons.
6. Operating Instructions
6.1 Selecting a Scan Mode
Press the MODE button to cycle through the available detection modes: Stud Scan (0.5", 1", 1.5"), Metal Scan, and AC Scan. The selected mode will be indicated on the LCD screen.
6.2 Calibration Procedure
Calibration is essential for accurate readings and should be performed before each scan or when moving to a new scanning area.
- Place the detector flat against the wall surface where you intend to scan. Ensure there are no known objects or wires directly beneath the device during calibration.
- Press the SCAN button (located on the left side of the device).
- Hold the device steady for a few seconds until the calibration process is complete and the screen clears, often accompanied by a short beep.
6.3 Scanning for Objects
After calibration, keep the SCAN button pressed and slowly slide the detector horizontally across the surface. The LCD screen will display indicators as it detects objects.
- Stud Scan: As the detector approaches a stud, indicator arrows will appear, guiding you towards the center. A 'CENTER' icon will display when the device is directly over the stud's center.
- Metal Scan: Similar to stud scan, arrows and a 'CENTER' indicator will guide you to the center of metal objects.
- AC Scan: The device continuously scans for live AC wires in all modes. A red lightning bolt icon will illuminate if live AC wires are detected. For precise location, switch to AC Scan mode. Arrows and a 'CENTER' indicator will pinpoint the wire's location.
The device will emit an audible alarm that becomes louder as it gets closer to the target, and the LCD display will show the direction of the target.

Image: Step-by-step guide illustrating the power-on, calibration, and scanning process of the detector.

Image: The LCD display indicates the direction and center of detected objects, accompanied by an audible warning.
7. Maintenance
- Cleaning: Wipe the device with a soft, dry cloth. Do not use abrasive cleaners or solvents.
- Storage: Store the detector in a cool, dry place away from direct sunlight and extreme temperatures. If the device will not be used for an extended period, remove the 9V battery to prevent leakage.
- Battery Replacement: Replace the 9V battery when the low battery indicator appears on the LCD screen to ensure optimal performance.
8. Troubleshooting
- Inaccurate Readings or False Positives: Ensure the device is properly calibrated on a clear section of the wall before scanning. Re-calibrate if moving to a different area or if readings seem inconsistent. Environmental factors or nearby electronic devices can sometimes influence readings.
- No Detection: Check if the battery is properly installed and has sufficient charge. Ensure the correct scan mode is selected for the target material.
- Buttons Not Responding: For button operations, a brief press is typically sufficient. Avoid prolonged 'push and hold' actions unless specifically instructed.
- Device Not Powering On: Verify the 9V battery is correctly inserted and fully charged. Replace the battery if necessary.
9. Warranty and Support
For warranty information, technical assistance, or customer support, please refer to the documentation provided with your purchase or contact the manufacturer directly through their official website or your retailer.