Solid Brass Brushed Nickel Rectangular Interior Shelf Clamp. Designed to be used to secure a shelf for lightweight articles. Clamps should be secured to wall with screws (included) in studs, or with Molly-type anchors. 2 Nylon tip brass set screws secure the glass. Maximum 5" (127 mm) glass protrusion from wall is recommended. Recommended use tempered glass for shelve. 3-5/16"(100mm) Wide x 1"(25mm)Deep.