Traditionally used to focus the beam in lighthouse lamps, a Fresnel lens replaces the curved surface of a conventional lens with a series of small, narrow concentric grooves on its surface. Compared to conventional, bulky lenses, our plastic Fresnel lens is thinner, lighter, and flatter and captures more oblique light from the source. This Fresnel lens is perfect for magnifying images. Used in conjunction with our book, Physics Demonstration Apparatus
, you can easily build a device that will melt pennies in as little as 30 seconds! 10.25 x 7 inches. About 12 inch focal length.