Introduction
The Alonefire SV57 is a compact and powerful 365nm Ultraviolet (UV) flashlight designed for a wide range of detection and identification tasks. Its specialized UV LED and black filter lens ensure a pure UV output, making it highly effective for revealing hidden substances and authenticating various items. This manual provides essential information on the product's specifications, safe operation, maintenance, and troubleshooting.

Safety Information
WARNING: DO NOT LOOK DIRECTLY AT UV LIGHT.
- Avoid direct exposure of UV light to eyes and skin.
- Keep out of reach of children.
- Do not disassemble the flashlight, as this may void the warranty and pose a safety risk.
- Use only the provided USB cable for charging.
Specifications
| Feature | Detail |
|---|---|
| Brand | Alonefire |
| Product Model | SV57 |
| Light Source | UV 365nm LED |
| Material | Aluminum alloy |
| UV Wavelength | 365NM |
| UV Power | 3W |
| Mode | 1 Mode (Single File) |
| Battery | Built-in 14500 lithium battery |
| Charger | Rechargeable (Type-C interface) |
| Dimensions (L x Head D x Tail D) | 86mm x 21mm x 21mm (3.39 in x 0.83 in x 0.83 in) |
| Weight | 55g (0.13 LB) |
| Waterproof | Yes |
| Focal Length | Non-adjustable (No Zoom) |
| Lighting Distance | < 50 m |
| Certification | ROHS, CE |

Package Contents
The following items are included in your package:
- 1x Alonefire SV57 LED UV Flashlight
- 1x USB Charging Cable
- 1x Storage Box
Setup
Initial Charging
Before first use, ensure the flashlight is fully charged. The SV57 features a built-in 14500 lithium battery and charges via a Type-C USB interface.
- Locate the Type-C charging interface at the tail end of the flashlight.
- Connect the provided USB cable to the flashlight's Type-C port and the other end to a standard USB power source (e.g., computer, wall adapter).
- During charging, a red indicator light will be visible.
- The indicator light will turn off once the battery is fully charged.


Operating Instructions
Turning On/Off
Press the power switch located at the tail end of the flashlight to turn the UV light on or off. The SV57 operates in a single mode (single brightness level).
General Use
For optimal results, use the UV flashlight in a dark or dimly lit environment. The 365nm wavelength, combined with the black filter lens, provides a pure UV output that effectively highlights fluorescent materials without excessive visible purple light.


Application Areas
The SV57 UV flashlight is suitable for various tasks, including:
- Pet Urine Detection: Irradiate suspected areas to observe fluorescence, indicating pet stains.
- Scorpion Finding: Scorpions fluoresce under UV light, making them easier to spot in dark environments.
- Currency and Document Authentication: Verify security features on banknotes, licenses, cards, and passports.
- Oil Stains and Leakage Detection: Identify hidden oil leaks or stains that fluoresce under UV.
- Ore and Antique Identification: Certain minerals and antique materials exhibit unique fluorescence under 365nm UV light.
- UV Glue Curing: Can be used for curing UV-sensitive adhesives.




Video demonstrating the Alonefire SV57 UV flashlight's features and various detection applications.
Maintenance
- Cleaning: Wipe the flashlight body with a soft, damp cloth. Do not use abrasive cleaners or solvents. Keep the lens clean for optimal performance.
- Storage: Store the flashlight in a cool, dry place away from direct sunlight and extreme temperatures.
- Battery Care: Recharge the battery regularly, even if not in frequent use, to maintain battery health. Avoid fully depleting the battery for extended periods.
Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Flashlight does not turn on | Low battery or no charge | Charge the flashlight using the provided USB cable. Check if the red indicator light appears. |
| UV light is dim or weak | Low battery; dirty lens | Recharge the flashlight. Clean the lens with a soft cloth. |
| Charging indicator light does not turn on | Faulty USB cable/power source; flashlight already fully charged | Try a different USB cable or power source. If the flashlight is already charged, the light will not appear. |
User Tips
- For optimal detection of pet stains, scorpions, or security features, always use the flashlight in the darkest possible environment.
- Hold the flashlight close to the surface you are inspecting for a more concentrated and effective UV beam.
- Regularly clean the lens to ensure maximum UV output and clarity.
- Keep the flashlight charged to avoid interruptions during use.
Warranty and Support
This Alonefire product is designed for durability and performance. For any warranty claims or technical support, please refer to the seller's policies or contact Alonefire customer service directly. Keep your purchase receipt as proof of purchase.





