Master Lock 178D Set Your Own Combination Padlock, 1-Pack, Black Indoor and outdoor padlock is best used as a school locker lock, gym lock, and gate lock, providing protection and security from theft Set your own four-digit combination lock for easy combination recall; combination change tool included Combo lock is constructed with a solid body for strength and weatherability, hardened steel shackle for cut resistance 2 in. (51Mm) wide lock body; 5/16 in. (8 mm) diameter shackle with 1 in. (25 mm) length, 1 in. (25 mm) width Note: shackle is preset to open on 0-0-0-0. Some instructions may incorrectly state shackle opens on l-o-c-k. See user manual in technical specifications section of this page for correct combination reset instructions.