The Master Lock No. 1525 1-7/8in (48mm) General Security 3-digit combination padlock includes with key control feature for supervisory access along with many enhanced security features like the exclusive BlockGuard Anti-Shim technology, hardened steel shackles and double-reinforced stainless steel casing. 3/4" shackle clearance length. Designed to fit lockers with a padlock eye of at least 5/16in (8mm) diameter.