Sensaphone Door Switch with Magnetic Reed Sensor Bridge enables your IMS-4000 system by Sensaphone to detect if any unauthorized entry or intrusion has occurred. Includes bridge and 10' RJ45 cable which may be mounted either on a wall or rest on the floor. The switch is mounted to doors or windows you wish to monitor. Note: FGD sensors, accessories, etc. are not compatible with IMS-4000 systems by Sensaphone.