"The optional RC2S will operate as any motion detector ( uses three "AAA" batteries -battery life about six months). As a person passes within the detection area of up to 20 feet the sensor will detect the person and relay a wireless signal to the receiver any where within a 70 ft. reception area. The sensor will also have a switch to turn it on or off. This wireless door chime may be worn as a pager ( will have 8 tones and powered by two "AA" batteries - ) or mounted an a wall or placed on a desk. The expected battery life is 4 months on the receiver. The warranty is one year. This is the only place on the web you will find this chime. When used with the RC 17 pushbutton door bell you will have the cost effective option of a different tone from the receiver for a delivery door or front door for your business should you wish to lock your door."
DING DONG TWICE