ELPA (Asahi Denki) Wireless Chime Door Opening Sensor & Receiver Set I am selling this as I no longer need it, having used it at my home's entrance. It functions well and is in clean condition with no noticeable scratches or stains, but there are traces of double-sided tape. Double-sided tape is required to attach the door sensor. Please note that double-sided tape and batteries are not included. The instruction manual is included.