Esky Ultraviolet Flashlight with 51 395nm LEDs

Esky 395nm LED Ultraviolet Flashlight  with 51 395nm LEDs

From the product page on Amazon.com:
List Price:    $39.99
Price:    $14.99 & FREE Shipping on orders over $35.

Friction Factor = LOW FRICTION
Value = RECOMMENDED
Esky UV Flashlight 2.jpg

This Esky ultraviolet flashlight has 51 395nm LEDs that provide bright UV lighting. It is light weight with solid aluminum construction and has a comfortable grip and easily accessible on/off button. It is also water resistant, good for outdoor use.

It uses three AA alkaline batteries, though some have reported that rechargeable batteries work (more limited charge). The specs indicate that the batteries are not included, but my review unit came with 3 Kirkland alkaline batteries. The specs do not mention the wrist strap that is included (it is shown in the photos).

At 395nm, the light has a strong visible violet component. On the plus side, this adds visibility when working in the dark. It may dilute the visibility of some fluorescing substances, but that did not seem to be a problem for me. Some things fluoresce better at shorter wavelength. The spectragraphic curve of an LED peaks at a rated wavelength, but the spectrum extends with some energy to either side, so this may be a good general-purpose flashlight. Some currency anti-counterfeit indicators are designed to fluoresce at 365nm, so your requirements will dictate if this is the right flashlight for you. I was able to easily see the anti-counterfeit strip on U.S. bills with this light. 

Here is a very helpful chart (assuming it is accurate) to know the best UV wavelength for given applications.