Simon 3: GE ITI Wireless Glass Guard Sensor 60-462-10-319.5 Can be added to a wireless home security system with video surveillance cameras and more An excellent choice for homes with big picture windows or for businesses with storefront glass. Can be mounted anywhere on glass at least 1" from the window frame 5' sensitivity area radius Works well with the Simon 3. Check with SafeMart for compatibility with Simon XT and Simon XTi.