Donegan Optical-OptiVISOR AL Headband Magnification Set. The perfect magnification set for your office, home, workshop or while doing crafts! The headband is adjustable and leaves your hands free. Tilts up for convenience. Can be worn over prescription or safety glasses. This package contains optical visor with one 3 diopter (magnifies 1-3/4X at 14 inches), one 4 diopter (magnifies 2X at 10 inches), one 5 diopter (magnifies 2-1/2X at 8 inches) and one 7 diopter (magnifies 2-3/4X at 6 inches). Made in USA.