“DIAMOND 6-LEVER” – 3 Arm Levers – No Pins – Letter Style 2 – Short “L” – High Shackle – SB Co – 1892. The “S.B.CO.” trademark is stamped on the obverse of the shackle. “PAT 1892” is stamped on the reverse of the shackle. There is no 1892 patent so I am going to assume that this is an error.Patent # 536844. (D-450).