CRL Solid Brass Shelf Clamps with Support Leg can be used to secure a shelf for lightweight articles. Clamps should be secured to wall with screws (not included) in studs, or with Molly-type anchors. Nylon tip brass tension screws secure the glass. Maximum 5" (127 mm) glass protrusion from wall is recommended. Clamps will hold 1/4" to 3/8" (6 to 10 mm) glass, with no glass fabrication required. "F" shape gives an extra 1/2" (12 mm) support against the wall. One Clamp per pack.