Realty Automation & Security Systems Pvt. Ltd. Manufactures Wireless Door / Window Sensor. Realty Automation & Security Systems Pvt. Ltd. Supplies electronic safety, security, surveillance & automation solutions to customers. Wireless Door / Window Sensor is a wireless sensor developed for use with V-cop Security System. Wireless Door / Window Sensor achieves enhanced wireless reliability using unique duplex narrow band frequency diversity which transmits and receives radio signals on two separate frequencies.