Princeton Tec Impulse Key Chain Light - LED

Handy, well-made and bright light. Five-mode feature is useful. As some other reviewers noted, this key chain light is on the large side, and it adds a significant amount of bulk if you're used to keeping your keys in your pants pocket.

Like the clasp that fits on a cap

I use it for all my keys - the only problem is that it is too thick for the holes on most keys, so I have my keys on another ring and attach the ring. Light is very strong, and is always there when I need it. I don't know about the colored lights - I got white, and ordered two more for my kids after getting the first one. I never tried the hat clasp, but that seems useful too when camping. Excellent product - I'll get more if they have white light again!

I'm a musician and works great in low light situations when giging.

I keep one on my key chain to provide light in dark areas such as parking lots. Use the hat attachment for cross-country skiing at night. Good for camping - finding things in the dark.