Vintage AMERICAN OPTICAL SURE-GUARD Safety Glasses. This item features the distinctive AO hinges, instantly recognizable as American Optical, and is a very popular model along with the TART OPTICAL ARNEL. The shape of the temple end, commonly called a "butter knife," suggests that this is an "early model" safety glass. While there are some minor scratches, it has a good overall luster and is in good condition for a vintage item over 60 years old. The metal parts are also free of rust and shine. There is no frame twisting, loose screws, looseness in the hinge hardware, or oxidation odor. Although gray smoke (clear gray) is often listed, black or 46-22 size is rarely offered. This is a very rare item, so we hope you will consider purchasing it at this opportunity. Markings: 46 22 on the back of the frame 4 3/4 American logo Optical on the inside of both temples Actual Size: Lens width: 46mm, height: 40mm Distance between lenses (bridge width): 23mm Frame width: 140mm, height: 47mm Temple length: 150mm Lenses: None Color: Black系 Frame Material: Resin/Plastic