This Hands-Free™ fold-up magnifier allows two-handed examination of objects. It provides a sharp, crisp, distinct image with vivid enhancement of details. Magnifiers have perfect focus with zero distortion. Designed specifically for use in quality control, labs, food, electronics, manufacturing, and universities. White ruler markings in both inches and millimeters on the lower panel assist in making measurements. All-glass optics assure perfect focus with zero distortion. Magnifiers fold twice for compact storage. Replacement bulb Cat. No. 8014. These are mainly used in assembly, electronics manufacturing, industrial inspection, medical/life science and also for use with foods or electronics. Magnification: 3.5 X. Lens Diameter: 2-Inch. Type/Mounting: Folding or linen. Lens/Optical System: Single positive lens. Control Company#: 3433.