Bests & Worsts Reviews from Amazon

WARNING: THIS IS NOT A TOY! Keep ALL UV flashlights away from children because UV RADIATION CAN CAUSE BLINDNESS. A notice on the flashlight warns against shining the light into your eyes OR EVEN SHINING THE LIGHT ON YOUR SKIN. Powerful UV lights similar to this one are used for curing and drying inks, adhesives and coatings. This is a review of the LIGHTFE ultraviolet flashlight which outputs a wavelength of 365nm. (Do not confuse this with model which outputs a wavelength of 395nm and cost a few dollars less.) UPDATE May 2019: CONTRARY TO WHAT THEIR OWN DOCUMENT SHOWS (see photo) the model designation for the 365nm flashlight is UV301D. The model designation for the 395nm is UV301A. This is a review of the LIGHTFE ultraviolet flashlight model UV301D outputs a wavelength of 365nm. As of the date I'm writing this review, I've noticed that FOR SEVERAL OF THE LIGHTFE FLASHLIGHTS, the product descriptions, technical specifications, questions and answers, and even THE REVIEWS HAVE BEEN CO-MINGLED. Also, a single specification might show two different wavelengths and/or two different battery configurations or battery sizes. So, you can use the price to determine which model you are ordering. The higher priced models have a higher frequency (and therefore a shorter wavelength). 365nm (nano meters) is shorter than 395nm. The UV301D is well designed. It comes in a box that includes one AA battery, two extra O-rings, a pocket clip, and lanyard. The operation of the tail-cap switch is click once for on, click once for off. I attached the pocket clip to the flashlight but was unable to clip it to my shirt pocket because the clip presses extremely hard against the flashlight. However, the "pocket clip" will securely hold the flashlight to the your pants pocket. I attached the lanyard and it works fine. However, attaching the lanyard was a challenge. If I had it to do over again, I would probably first feed some thread through the lanyard holes, and then use the thread to pull the lanyard through the holes. The user manual says that the battery output is regulated to provide a constant brightness and that the batteries should last 2.5 hours. The battery may last 2.5 hours, but NOT with constant brightness (see my test data below). It's drawing a lot of power from the single AA battery. To get 3 watts out of a 1.5 volt battery requires 2 amps! The trade-off is that it provides a lot of UV light output WHEN THE BATTERY IS NEW. This is a good trade-off because you get an extremely bright flashlight in a compact size. I ran a test using ZTS battery tester that I got right here on Amazon. (Please see photo.) I started with a new battery. The tester showed the battery charge was 100%. Using a digital timer, I ran the flashlight for 5-minute intervals and then checked the battery after each interval. The tester showed that the battery ran down quickly. Here is the data from my test of the UV301D. Elapsed Percent Time . . . Charge 00:00 100% 05:00 80% 10:00 60% 15:00 40% 20:00 40% 25:00 40% 30:00 40% 35:00 40% 40:00 40% 45:00 40% 50:00 40% 55:00 20% 60:00 20% 65:00 20% Stopped test overnight Resumed test. (The battery recovered a bit by letting it "rest" overnight.) 70:00 40% 75:00 40% 80:00 20% 85:00 20% 90:00 20% Of course, the amount of charge left in the battery is not as important as the amount of UV light emitted from the flashlight. At 90 minutes, the light was not nearly as bright as when the test started, but the amount of light was still useable. To see a list of model numbers and associated wavelengths, scroll to the top, find "by LIGHTFE" near the top of this page, and then click on LIGHTFE. For more info, use your browser search function to find "PDF" on this Amazon webpage, and then click on "Specification Sheet".