The MagniMark (MM-22) from Carson is a fresnel page magnifier that contains a built-in 6 inch ruler. Each fresnel magnifier contains a 3x power magnification. The MagniMark magnifiers are extremely thin and light weight. The wide viewing area of each magnifier makes them ideal for reading books, magazines, coupons, recipes, phone diretories and so much more! Use the MagniMark as a bookmark or a place holder while reading your favorite book or magazine. The MagniMark magnifier is backed by Carson. At Carson, we strive to make sure our customers are 100% satisfied with the quality of our magnifiers. Carson will repair or replace your magnifier if it is found to have manufacturing defects in materials or workmanship..