The split in the ribbed anchors expand on two opposing sides when you tighten up the screw, it increase the holding power. Anti-rotation structure design of the expansion sleeve able to tighten the screw, Hence, will not follow in the drilling rotation. These drywall anchors and screws are suitable for gypsum board, decorative panel, asbestos board, hollow board and etc. It good for blinds, shelf, curtain installation, lamp installation ,art pendant installation and etc. How to use: Just fold the anchor in middle, insert into a hole, and tap flush. Thread a screw through your fixture and into the anchor. Ribbed nylon expansion tube need to open 8-9mm drilling hole, board thickness about 8-15mm.