Usage Tips:Our neodymium round base disc magnets are made of neodymium metal material, which makes their magnetism very strong. Each round magnet is 0.78 inch (20mm) in DIAMETER and 0.22 inch (5.5mm) in HEIGHT. PULL FORCE: 40 LBS+ (Vertical)These strong magnets with hole are made of NdFeB material with a nickel-plated coat for maximum durability and protection against corrosion. Steel cups protects magnets from breaking which greatly increase the of the neodymium magnetsInstallation is a simple matter with our Countersunk Hole Magnetic Discs. 24 mounting screws are included, making it easy to use them in two different ways. These industrial magnets can be used on metallic items as well as non-metallic items. The Neodymium cup magnets have a countersunk center hole that is perfectly designed for mounting with a flat head screw or bolt.These heavy duty strong magnets are great above the workbench to hold tools that you use consistently, so they are within . The powerful neodymium cup magnets will some of your heavier hand tools quite well and very . Perfect for organizing and hanging in workshop, and decluttering your home, garage, business and schools. Holding, Lifting, Fishing, Closing, Retrieving, and much moreColour:B:BlackMaterial:MetalSize:11.10 x 5.69 x 1.70 cmPackage Contents:1set * neodymium magnetOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.