Installs quickly with removable wing knob. 24/7 security monitoring. Remote open from anywhere. Real-time reminders. Wi-Fi connectivity. Loud, audible and visual alerts from device. Back up key access. Sealed compartment to control moisture. Exterior dimensions (wings retracted): 6'' x 12.8'' x 3.4''. Exterior dimensions (wings extended): 6'' x 22.6'' x 3.4''. Interior dimensions: 4.6'' x 8.4'' x 2.5''. Weight with batteries installed: 4.15 lbs. Smart phone app available for IOS and Android systems. Requires (4) AA batteries (not included). Boxed.