Note: This expansion screw has four sizes of M6, M8, M10, M12. For more specifications, please see our photos. Package: includes 4 expansion bolts. 304 stainless steel material, corrosion and rust resistant, fixed and durable. The surface is flat and smooth without burrs, high quality workmanship, strong and durable. The screws are sharp and clear, and the force is uniform and not easy to slip. Expansion hook installation method: first drill a hole in the wall the same size as the expansion tube with a drill bit, then put the expansion hook into the hole, tighten the hex nut with a wrench, and finally open the tail of the expansion tube after being urged Hang on the wall. Expansion hook installation method: first drill a hole in the wall the same size as the expansion tube with a drill bit, then put the expansion hook into the hole, tighten the hex nut with a wrench, and finally open the tail of the expansion tube after being urged Hang on the wall. Professional standard expansion bolt hook, ideal for garage workshops, heavy construction, woodworking and home DIY. A wide range of applications, can be used for concrete and masonry, ceilings, etc.