✅Red/green reassurance LED. ✅When isolated, the QT604's reassurance LED will illuminate Green and the monitored door or device may be opened and closed without signalling a call on the system. ✅Mounts on a standard UK 25mm single gang flush or surface back box. ✅QT604M secure magnetic reset version also available. ✅A keyswitch-isolatable monitoring point with a reset button for cancelling calls, Manufacturer: C-Tec