The Pinhead seatpost lock prevents removal of your seatpost. Once installed, the seatpost lock remains permanently on your bicycle, even when you ride. When you need to adjust your saddle height, your Pinhead key lets you do this quickly and easily. Pinhead locks cannot be removed with tools such as hammers, pliers, picks, universal socket tools, grinders or bolt cutters. Our convex disc technology prevents your parts from being removed by bike thieves. Our locks use a special coded key. The key is ergonomically engineered to install and tighten your locks, and also serves as a bottle opener. Each key is different, and comes engraved with a nine-digit code so it can be replaced if lost. With your key code matching locks can be ordered to protect your other components or other bikes. All components are precision forged from corrosion-resistant CrMo steel and aircraft aluminium alloys. Pinhead locks are unmatched in quality, and backed by lifetime warranty.Key Features: Seatpost or Saddle security Fits all seat tube and seatpost sizes Fits saddles with vertical attachment bolts Uses QR coded key Easy saddle height adjustmentHella Slingshots