A versatile UV light that uses a 21700 size battery. The user interface includes two power output levels and light output ramping so the light needs better user instructions included with it, thus the downgrade to 4 stars on Amazon in my review. No mode memory so a momentary press has it come on in high mode. A second momentary press has it change to intermediate output mode and a third momentary press turns it off. A press and hold from on has it go into ramping mode, either up or down. When it reaches adjustment extremes the light blinks twice then starts ramping in the opposite direction until the switch is released. NONE of this is covered in the included documentation with mine.
The beam is fairly diffuse and beyond about a foot or so the center brightest spot turns into a doughnut with a dimmer center, so not an ideal beam in my opinion. The light itself seems to be quite well made and the UV filter is very good at eliminating light other than the wanted UV.
The light includes both USB A and USB C charging ports. The Amazon listing indicates that you need to charge the battery when the light gets dim so it appears that it does not include over discharge protection though it does include a 4 light battery charge level indicator that stays on when the light is on so I would recharge it when only one light is lit.