Lighthouse Precision Magnifier (3 lens system), 20x magnification. Professional quality. Triple lens system. Diameter: 3/4 (18 mm). Achromatic and aplanatic lens. Chrome plated casing. Foldaway. Comes with protective leather case. Dimensions: 3/4 x 3/4 x 1 1/4(20 x 20 x 32 mm).