The Master Lock No 4400EURD Indoor Smart 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 Smartphoneapp interface offers speed ease of use & greater control with the ability to share access with keyless convenience The locking mechanism features anti-shim technology offering maximum security It is supplied with an easy to replace CR2450 battery and has low battery notification and reminder on the padlock and app It has a battery jump that allows for temporary access if the battery dies while locked Width 47mm Depth 27mm Height including shackle 80mm Vertical shackle clearance 22mm Horizontal shackle clearance 22mm Shackle diameter 7mm