Brass body. Brass shackle. Keyway: Flat. “PATENTED JAN.7.1890” is stamped on the obverse of the shackle. “YALE & TOWNE MFG. CO. STAMFORD, CONN. U.S.A.” is stamped on the reverse of the shackle.Patent # 418884. (PK-LB-084-S2P).