The Master Lock 175D Set Your Own Combination Padlock features a 2in (51mm) wide solid body for strength and reliability. The 5/16in (8mm) diameter shackle is 1in (25mm) long and made of hardened steel, offering extra resistance to cutting and sawing. The 4-digit dialing allows for thousands of possible numeric combinations. The Limited Lifetime Warranty provides peace of mind from a brand you know and can trust. Indoor and outdoor padlock is best used as a school locker lock, gym lock, and gate lock, providing protection and security from theft.Note: Measure your door's backset, cross bore and thickness to ensure you find the right fit. 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 inch (51 millimeter) wide lock body; 5 by 16 inch (8 millimeter) diameter shackle with 1 inch (25 millimeter) length, 1 inch (25 millimeter) width Shackle is preset to open on 0-0-0-0; See user manual in technical specifications section of this page for combination reset instructions