The Master Lock No. 1594 Letter Lock™ shrouded combination padlock with key control feature for supervisory access use letters instead of numbers for easier combination recall with an easy-to-remember phrase for additional convenience. These locks also include many enhanced security features, like a shackle shroud to prevent shackle cutting or shimming, the exclusive BlockGuard® Anti-Shim technology and a hardened steel shackle. Designed to fit lockers with a padlock eye of at least 5?16in (8mm) diameter, these locks provide multiple customization options to fit your needs.