Modern headlamps with LED bulbs have made it really easy to carry a light with you while in the backcountry. This is a great safety item that takes little space in your pack and weighs almost nothing (3.5 oz.). This is especially handy in the winter when days are short. A small light on the white landscape makes traveling pretty easy. I ski at the end of the day quite often and end up using a lamp on my return.
I have been using the Snap Solo most of this winter, and find it serves my needs well. It is simple and has a 300 lumen light, plenty for traveling along on skis. It also can be made dimmer/brighter by holding the on button down. The Snap Solo has a nice removable lamp with a magnet on it so you can attach it to a car hood or whatever is steel/iron.
It is water resistant (IPX4) but not submersible. Colors are dark green and dark blue.
It comes with 3 AAA batteries.