The Master Lock No 4401DLH Bluetooth padlock features a 2732 in 56 mm wide metal body for durability The 1132 in 9 mm diameter shackle offers 2 in 51 mm vertical clearance and is made of boron alloy, offering maximum resistance to cutting and sawing The smartphoneapp interface offers speed, ease of use, greater control with the ability to share access, with keyless convenience The locking mechanism features antishim technology, offering maximum security The 1 Year limited warranty provides peace of mind from a brand you can trust Metal Body