Close shackle hardened steel armoured cover over steel body and brass cylinder hardened steel rotating shackle prevents cutting with any type of saw anti drill cylinder with ball bearing locking mechanism includes 3 steel keys horizontal x vertical shackle clearance 819718 20x15mm 380651 30x25mm 792082 36x25mm shackle dia 819718 10mm 380651 12mm 792082 12mm