When choosing a purple light flashlight, you need to consider 365nm and 395nm

Common UV flashlights include LED flashlights that provide 365 or 395 nanometer (nm) wavelengths. Different wavelengths affect how UV light is absorbed into the material and how the material fluoresces under UV light. Typically, 365 nm UV is more intense than 395 nm UV. For example, a 365nm UV flashlight is better at illuminating tiny stains, cracks and dry spots of liquid than a 395nm UV light. At the same time, 365 violet flashlights are also usually more expensive. As for the 395 nm violet light flashlight, because of its longer wavelength, it will emit more visible light relatively. If you want to have a brighter, wider beam and do not consider detecting the smallest stains and spots, the 395 nm black light flashlight is more suitable your requirements. And for precise uses like analyzing currency, UV light at 365 nm is better because it produces less visible light, so fluorescent materials can be seen more clearly.

The purple light flashlight with rechargeable battery can not only reduce the cost of purchasing disposable batteries but also be more environmentally friendly. Disposable batteries are more convenient, you can buy common types of dry batteries from the store at any time, and you don't have to wait for the time cost of charging.