15mm Diameter The original 'Linen tester'. Although deriving its name from the textile industry it is also suitable for inspecting paper, photographs, printed documents etc. 15mm diameter glass lens. 7x magnification. 1" working distance. 1/2" square field. Inch graduation. 1/8" divisions. Self-standing to free your hands. Folds flat when not in use. Black powder coated body.