1. Introduction
Thank you for choosing the VASTFIRE UV 365NM Ultraviolet Blacklight Flashlight. This device is designed for various detection purposes, utilizing a 365nm UV light source to reveal substances not visible under normal light. Its applications include detecting pet urine stains, cat moss (tinea), counterfeit currency, fluorescent agents, and more. This manual provides essential information for the safe and effective use, setup, operation, and maintenance of your flashlight.
2. Safety Information
- UV Light Exposure: Avoid direct exposure of UV light to eyes and skin for prolonged periods. UV light can be harmful.
- Children: Keep the flashlight out of reach of children.
- Heat: The flashlight may become warm during extended use. This is normal.
- Water Resistance: The flashlight has an IPX45 waterproof rating, meaning it is protected against splashing water from any angle. It is not designed for submersion.
- Battery Safety: Do not attempt to disassemble or replace the built-in lithium battery. Do not expose the battery to extreme temperatures or fire.
3. Package Contents
Please check the package for the following items:
- 1 x VASTFIRE UV 365NM Ultraviolet Flashlight
- 1 x USB Charging Cable
4. Product Overview
The VASTFIRE UV 365NM flashlight features a durable aluminum alloy body and black lenses designed to filter out visible light, enhancing the clarity of UV detection. It includes a built-in rechargeable battery and offers a 5-speed lighting mode.


5. Specifications
| Feature | Detail |
|---|---|
| Model Number | UV 365nm ultraviolet flashlight |
| Brand Name | VASTFIRE |
| Material | Aluminum alloy |
| Color | Black |
| Power | 5W |
| Voltage | 3.7V-4.2V |
| Lamp Beads | LED |
| Lumens | 400lm |
| Charging | USB charging |
| Battery Type | Built-in rechargeable lithium battery |
| Battery Capacity | 1200mAh |
| Special Function | Can be used as a mobile power supply (power bank) |
| Lighting Modes | 5 levels (Strong light, Medium light, Low light, Burst flash, Slow flash) |
| Effective Detection Distance | Within 50cm |
| Waterproof Rating | IPX45 |
| Flashlight Size | 175mm * 28mm |
| Net Weight | 147g |
| Focal Length | Non-adjustable |
| Light Source | Fluorescent |
| Certification | CCC, CE, ROHS |
| Switch Mode | High/Middle/Low |
| Zoom | No |
| Item Type | FLASHLIGHTS |
| Origin | Mainland China |
| Support Dimmer | 5 - 8 Files |
| Flashlight Type | Detecting cat ringworm, urine, currency, jewelry, fluorescent agent |
| Lighting Distance | 100-200 m |
| Lumen | > 350 |
6. Setup
Before first use, it is recommended to fully charge the flashlight. Refer to the "Charging" section for instructions.
7. Operating Instructions
To operate your VASTFIRE UV 365NM flashlight:
- Power On/Off: Press the switch button (refer to Figure 1) to turn the flashlight on. Press it again to turn it off.
- Cycle Lighting Modes: While the flashlight is on, press the switch button repeatedly to cycle through the 5 lighting modes: Strong light → Medium light → Low light → Burst flash → Slow flash.
- Detection: For best results, use the flashlight in a dimly lit or dark environment. Shine the UV light directly onto the surface or object you wish to inspect. The black lenses help to block ambient light, making fluorescent substances more visible.



Product Working Principle for Fungi Detection
The flashlight utilizes the principle that tryptophan, a metabolite in the growth and metabolism of animal hair, emits characteristic golden yellow or yellow fluorescence under the illumination of Wood's lamp (UV light). Different fungi may exhibit distinct fluorescence colors:
- Red ringworm: Red
- Coccidioides: Yellow Green
- White Ringworm: Brilliant Green Fluorescence
- North American budding bacteria: Yellow Green
- Yellow ringworm: Dark / Dark Green
- Aflatoxin bacteria: Blue, Yellow-green
- Tinea versicolor: Wax Yellow
- South American Budding Bacteria: Yellow
- Mucor Mushroom: Orange Red
- Actinomyces: Red to Yellow
- Small spore ringworm: Light green
- Gray spot: Blue and white
- Scabies: Off-white
- Black ringworm: No fluorescence
- White tired wind: Blue white to Bright white
- Nocardia: No Fluorescence
8. Charging
The flashlight is equipped with a built-in 1200mAh rechargeable lithium battery and supports USB charging.
- To Charge the Flashlight: Connect the provided USB charging cable to the USB charging port on the flashlight (refer to Figure 1). Connect the other end to a compatible USB power source such as a computer port, portable power bank, or a USB wall adapter.
- Power Bank Function: The flashlight can also act as a mobile power supply to charge other devices. Connect your device's charging cable to the USB discharge port on the flashlight (refer to Figure 1).


9. Maintenance
- Cleaning: Wipe the flashlight body with a soft, damp cloth. Do not use abrasive cleaners or solvents.
- Lens Care: Gently clean the black lenses with a soft, lint-free cloth to maintain optimal detection clarity.
- Storage: Store the flashlight in a cool, dry place away from direct sunlight and extreme temperatures. If storing for extended periods, charge the battery every 3-6 months to prolong its lifespan.
10. Troubleshooting
- Flashlight not turning on: Ensure the battery is charged. Connect the flashlight to a USB power source and allow it to charge for at least 30 minutes before attempting to turn it on again.
- Light is dim: The battery may be low. Recharge the flashlight.
- Detection is unclear: Ensure you are using the flashlight in a dark environment. Clean the black lenses if they appear dirty or smudged.
- Device not charging from flashlight (power bank function): Ensure the flashlight has sufficient charge. Check the connection between the flashlight's USB discharge port and your device.
11. User Tips
- For optimal detection of pet stains or other fluorescent materials, use the flashlight in a completely dark room.
- When checking for cat moss (tinea), ensure the cat's fur is dry, as moisture can interfere with fluorescence.
- The black lenses are crucial for filtering out visible light, making the UV effect more pronounced. Keep them clean.
12. Warranty and Support
For any product inquiries, technical support, or warranty claims, please contact the seller or manufacturer directly through your purchase platform. Keep your proof of purchase for any warranty-related services.