CRL No-Drill Glass Shelf Clamps are made of solid brass with a beautiful chrome or gold plated finish. They make mounting small glass shelves directly to walls or inside cabinets easy because nylon set screws secure the glass, so absolutely no glass drilling is required. The Long Clamps are available in two lengths, 1-1/4" and 2-3/4" (32 and 70 mm) for 3/8" and 1/2" (10 and 12 mm) glass. Maximum shelf protrusion from the wall is 5" (127 mm). Shelf Clamps are also suitable for use with small acrylic or wood shelves. The "Back Wall" thickness of the Clamp is 1/4" (6 mm).