While not as small as our credit card sized fresnel lens, this lens is still small and light enough that you can slip it just about anywhere in your pack and you will never notice it until you need it. A fresnel lens is a fast and efficient way to start fires on a sunny day. Fresnel lenses act like magnifying glasses, which means that you can focus the sun's rays on a small point to instantly light many kinds of tinder. Char cloth works especially well in combination with a fresnel lens.
