These ribbed plastic anchors are designed for light-duty anchor applications. Ribs prevent the anchor from turning in the hole during installation. They expand as the screw is tightened for a secure hold and feature a split to ensure expansion on 2 opposing sides. Pre-drilling is required, masonry drill bit included. Insert anchor flush with surface. Not recommended for ceiling applications.Includes 100 anchorsIncludes 100 phillips/slotted screwsIncludes 1 masonry drill bitReusable plastic carrying case