Fishing 100LM 3-Mode 1-LED Blue Light Flashlight (3 x AAA or 1 x 18500)

Pros: I haven't checked the wavelength of this light, but it works very well for detecting UV dye in automotive uses, which is what I bought it for. With 18500 batteries this light is very bright. With the adjustable focus it's easy to illuminate an engine compartment on high power, then switch to lower power and fine tune the focus to pinpoint leaks. I'm very pleased with the functionality as a leak detection aid.

Cons: The body of the light is all plastic and feels flimsy compared with other focusable lights from DX. That being said, for typical use I don't expect any service life complaints.

Other: You cannot really go wrong with this light if you need a bright, adjustable focus UV LED light. The light comes with a holder to fit 3 AAA batteries, or remove that and use one 16500 battery. They market this as a "blue" LED light, and the appearance is slightly more blue than a typical UV light, but it still works excellent as a UV light.

Pros: Easy to use. Adjustable zoom/focus.

Cons: A little to blue to be a good UV light. It still works as one but there is a lot of blue light emitted. When I bought this light it was listed as "UV" but now I see it's been changed to "blue". So if you're buying it as a blue light then disregard this con.

Other: If you want a focusable blue light - get it. If you want a UV light - don't get it.