Check the listing for details. nib novitas 01-072c one way room sensor. Condition: New. Listed at 27.99 USD. this is a new in the box novitas 01-072c one way room sensor this unit ahs a ultrasonic motion snesor with built in timing and load control relay driving circuitry. the sensor produces a low intensity inaudible sound. it detects changes in the sound waves caused by motions such as waling into a room, reaching for a telephone, turning in a swivel chair, etc. the sensor does not respond to audible sound. for use in areas from 500-900 square feet. ask other questions you have --- please please take in this info. i can only ship mon-wed. i work another full time job and where i list from is an hour from where i live. if you can not accept this, please do not buy. by not reading this info and leaving low markings on shipping time, you are hurting my feedback score and ratings!! i try to do my best and love selling. please do not forget this when you leave your feedback for the shipping time!! thanks so much