General description UNIOR Bottom Bracket Socket 16 Notch is a precision CNC machined tool designed for the installation and removal of various external bottom bracket cups. Made from aluminum billet and anodized in red, this socket offers a durable finish and a precise fit that prevents damage to aluminum external bottom bracket cups. Technical specifications Material: Aluminum billet Finish: Anodized red Drive type: 1/2" square drive Notch type: 16 notch Usage Designed for installation and removal of external bottom bracket cups Knurling on the side provides better grip for hand threading Compatible with torque wrenches, ratchets, and fixed handles