The Master Lock No 4401LHEC features a 2732in 56mm wide metal body for durability The 1132in 9mm diameter shackle offers 2in 51mm vertical clearance and is made of boron alloy, offering maximum resistance to cutting and sawing Secure your home or business with the Master Lock Vault System for unmatched security, simplicity and accountability using the latest in Bluetooth lock technology from Master Lock These locks withstand physical attacks and hacks, protecting your property with military grade encryption and highsecurity features Administrators control individual or systemwide lock access with our convenient app and web interface options, while users enjoy simple, secure access to assigned locks or lock boxes