An indespensible vision aid for use as a reading aid or industrial clinical and hobby applications, The Spring-Clip Opticaid has ophthalmic hard-coated lens that is both lightweight and comfortable, Swings up when not in use New design fits metal and plastic frames Fits bifocal unifocal or half-eye WILL FIT ALL MODEL FRAMES INCLUDING HALF-EYES AND SAFETY GLASSES ""MEMORY"" PLASTIC WITH HEAVY DUTY METAL SPRING SOFT-COATED PRONGS POWER:2, 75 X W, D, -6 "" DIOPTER:+7D SKU: EDRY022