Survival Fire Starting lens uniquely designed by Eric Boettcher Survivalist. This is not your childhood magnyfying glass to burn ants. A fresnel lens is designed with a unique groove pattern much like a fingerprint to increase the surface area which in turn generates greater amounts of heat. They are primarily used in televesions and light houses. Eric Boettcher Survivalist designed a patent pending survival fire starting lens that is floppy, durable, light weight and can burn pretty much anything. What is the difference? He raised the fingerprint groove a little taller and therefore makes his fresnel lens a true survival fire starter. Just focus the lens with the angle of the sun and you have yourself a flame!