Indoor and outdoor padlock; maximum security lock with Tough-Cut octagonal boron-carbide shackle; best used for residential gates & fences, sheds, workshops & garages, storage lockers, tool boxes and more.Note: Measure your door's backset, cross bore and thickness to ensure you find the right fit. Lock is constructed with solid steel for increased strength and security; protective bumper for scratch resistance Four pin cylinder and dual ball bearing locking mechanism provides maximum pick and pry resistance; Tough-Cut octagonal boron-carbide shackle is 50% harder than hardened steel 1-3/4 in. wide lock body; 9/32 in. diameter shackle with 2 in. length, 13/16 in. width; extended shackle for application flexibility Includes four padlocks, two keys; Each key opens all locks