The K7DC Kit contains #10 Square Drive Sheet Metal Screws and #22 Plastic Conical Anchors that are suitable for use in solid and hollow wall, concrete, block or brick applications. When used in hollow walls, such as drywall or plywood, the wings will splay out to provide a more secure installation and higher pull-out load. The anchor has a lip to prevent falling into deep holes or hollow walls. For hard wall applications, use the size of the anchor to determine hole size for installation. For drywall or soft applications it is recommended to use the smallest hole that will enable a tight fit of the anchor. These anchors are not recommended for use in overhead applications or where holding values are critical.