The Standard 138-22 3S Drawer Lock is a widely used, heavy-duty cam lock designed for securing office furniture, filing cabinets, cupboards, and toolboxes. The “138-22” indicates a standard cylinder size of 19mm (3/4 inch) in diameter and 22mm in length, making it ideal for standard thickness drawers (approx. 17mm-22mm). “3S” indicates the inclusion of three keys, usually computerized or high-precision brass keys, for security and convenience