This aluminum alloy Round Magnetic Holder is our latest and strongest Magnetic Smartphone and Tablet holder. It comes with 9 N54 Magnets. The Round Magnetic MagSafe holder comes with a 21mm CNC Machined Aluminum Alloy Ball with special grooves for anti-slip. The rear comes with a female 1/4"-20 internally threaded thread for various mounting options. The aluminum alloy ball on the back side is removable but can be permanent if you use Loctite on it which you can buy separately online. This set also comes with 3 Ring Plates in this kit. When using ring plates please press firmly against flat surface of inner side of smartphone case or outer part of smartphone case. Allow 24-48 hours to dry. When First attaching plates apply pressure for about 5 minutes pushing firmly onto either outer side of smartphone case or inner side of smartphone case. Can also be mounted directly on smartphone if you don't have a case. When using do not pull directly off. Use peel method like flipping a page in a boom or a magazine to attach and detach smartphone or table when using.