Features: Make of neodymium iron boron, it provides excellent magnetic adsorption ability. The outer layer of the Rubberised structure effectively protects the magnet body, avoiding rust and wear. Widely applicable to various metal surfaces, easy to achieve quick installation and disassembly. It can be completed without the need for tools. Each rubberised magnet comes with spring washer, washer and screw. Simply attach it to your item and then attach it to a magnetic surfaces. Suitable for fixing car lights, doorbells, cameras, solar lights and workshop tools. Perfect for attaching light strips, reflectors or brackets to vehicles, garages or outdoor equipment. Specifications: Component: Neodymium Iron Boron Type: External Thread/Internal Thread Diameter: 22mm(0.87inch)/43mm(1.69inch)/66mm(2.6inch)/88mm(3.46inch) Package Includes: 1pc Strong Rubber Coated Mounting Magnets note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item.