The Master Lock No. 4400EURENT Bluetooth® Padlock features a 47mm wide metal body for durability. The 7mm diameter shackle offers 22mm vertical clearance and is made of boron alloy, offering maximum resistance to cutting and sawing. 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.