Review on Alonefire H42UV: High-Powered 36W 365nm USB Rechargeable UV Flashlight - Ideal for Pet Urine Detection, Resin Curing, Fishing, and Scorpion Hunting with UV Protective Glasses and 4xLithium Battery by Sarah Nguyen

I already had a smaller Alonefire SV41 10W and was very impressed with it. This 36 watt H42 is like holding and powering 3 SV41 together in the same range. The H42 has much wider beam coverage, but peak brightness appears to be the same. I could not have taken these photos without the wider UVa H42 beam. I live in the Arizona desert and this is a boulder in my backyard. The area is approximately 2 feet x 3 feet on the north side of it. There are 3 different lichens that I have never heard of before UV at night. Close inspection reveals 3 different types of daylight images. The H42's beam size is not as wide and can be used for faster reconnaissance coverage. It has sufficient brightness over a larger area but not too wide. The UV filter is glass. I'm glad I can afford both. I reviewed the SV 41 on the rocks and it was great. If you have small hands, it will be difficult to hold and operate this device with one hand. I liked the red to green loading feature.