Stanley Hardware S690-337 CD743 Butt Marker  in Black Coated Authorized Replacement from National Hardware Stock #N303-990 Designed to mark mortise on residential hinges Black, corrosion protective finish Manufactured with heavy gauge cold-rolled steel Designed for residential hinges Used to accurately mark the correct hinge size and proper mortise depth Made of steel Black baked-on enamel finish 3-1/2-inch length