Sturdy Polycarbonate hook flexible and high heat tolerant Buit-in super strong Neodymium Magnet Installs on any rod up to 1 inch diameter Used on all Mirortags & WindshieldTAGs placard holders Mdae in USA Many drivers who use use our Mirortag or WindshieldTAG holders have multiple cars and one tag issued, so instead of removing the hook from one car to another every time you drive a different car, you can get extra hooks for as many cars as you have and hang one hook in each car, and only transfer the tag holder between cars. It is made from a clear heat resistant and durable plastic. Works on all Mirortag & WindshieldTAG models.