“U.S.M.C. U0912 No 2 MASTER…”. Body Type: Laminated. Body Material: Brass. Body Size: 1 3/4″Wx1 3/8″H. Shackle Material: Brass. Shackle Size: 5/16″Dx5/8″H. Model No: No. 2. Key Type: Single Sided 4 Pins.