Laminated 1-3/4 steel padlock. Octagonal boron carbide shackle. 50% harder than hardened steel. Nearly impossible to cut with bolt cutters. Stainless steel top/bottom caps. Ball bearing locking. Rust free dual armor outer construction. Stainless steel top/bottom caps. Product performance test at the top of ASTM standards. Chisel resistant, recessed rivets. Larger, improved rear body bumper.