The Master Lock No. 6400ENT Bluetooth® Padlock features a 2-7/16in (62mm) wide metal body for durability and security. The 11/32in (9mm) diameter shackle offers 1-3/8in (34mm) vertical clearance and is made of boron alloy, offering maximum resistance to cutting and sawing. Weather cover provides enhanced resistance to perform in snow, rain and temperature extremes. The Master Lock Vault Enterprise system is designed to support Many Locks and Many Users with unmatched security, simplicity and accountability. Administrators control individual or system-wide lock access with our convenient web interface, while users enjoy simple, secure access to assigned locks or lock boxes.