SmartGate iSG-GWS-101 Wireless Magnetic Sensor is a 2-piece signal that affixes to door/gate frame and door and works with the iSmartGate security kits. Compatible with sliding, folding, swing gates, roller doors and side sectional doors. Even works on side-action sliding sectional doors. Works by creating magnetic signal. Communicates when signal, field is 1) being maintained, 2) has been broken or 3) gate has been left open. Wireless use and wireless install. Monitors gate or garage door up to 10 m from iSmartGate hub. Sends alerts via notifications or email directly to iSmartGate app on phone. Garage doors left open from the morning rush no longer a problem as this setup gives notifications if gate or door is left open.