these little lights are great for examining ophthalmology patients. They are inexpensive to I have give one to each of my resident physicians to keep and it doesn't weigh them down.Needed these for a team of medics over in the Ukraine. Being red, they are significantly more expensive than their black counterparts made by the same company. The red body isn't ideal for use in combat. I ended up taking them apart and painting the insides to subdue them a little.Great little light! BUT, I was unaware that the color of the light would be the same as the casing. I was NOT expecting a blue light.These are great to have for use in places where you do not want to bother others with a bright white light. Think movie theaters, airplanes, nightclubs, etc. Tiny and attach to your key chain. Glad there are six as they are easy to lose.Use these on my dog’s collar at nighttime. Clearly visible at long distances. Very bright. Lost one in the yard when dog was romping around. Carabiner failed and it came off—not the unit’s fault. Considering buying another set, just incase the manufacturer stops selling them. Amazing price to value, vs other sellers of same/similar concept (NiteIze, Inova, ASP, etc).Put another on my keychain for task lighting, which is getting more use than my iPhone’s flashlight since it’s more accessible/convenient. One could argue it’s too bright for night vision, although it’s clearly red. Personally, I don’t feel that way.I use in a hospital to check on patients and it does not wake them. Great lightThe light performed as advertised. Good quality for the price.I rated the brightness 5 stars because it is not too bright, since I use them with a telescope. Just guessing on battery life since I have not worn one out yet.I like the fact that these mini flashlights are very lightweight don't weigh down my key chain. I also appreciate the fact that I have the option of continuous light instead of just flashing light. These two advantages were a big factor in chooing these lights.I bought the 'party pack' of 7 different lights and I'm happy it gave me a choice because not all colors perform the same. The best are the white and black who both have a bright white light. The others would be ok (if you like weird lighting in a dark parking lot!), but the purple one is just about useless, I don't know if I just ended up with a dud but the purple one I got isn'r good for much.All in all, I am satisfied with my purchase and would buy again but, next time, would go with a set that gives out all white light.Bought them for my dog walks at night. 2.5 hours in and they start to fade. 2/6 lights used, hopefully the remaining four lights will last as advertised.Excellent product at a good price. I use them to get to my hunting stand and the amount of light is more than enough to walk in pitch black darkness.Switch is very difficult to move and turn device on and off, nail breaking adventure.Great mini red leds. They definately do the job. I am happy with them.