Armoured hardened steel shackle defies cutting. 1.9/16''/40mm laminated steel body for superior strength. 4 pin tumbler cylinder helps prevent picking. Shackle guard protects against bolt cutters and hacksaw’s. Ideal for securing trailers, cables and chains. Shackle fits openings 1/2''/13mm in diameter or larger; shackle guards removable to accommodate openings 7/16''/ 11mm in diameter.