Lutron LRF2-VCR2B-P-WH Radio Powr Savr Wireless Ceiling-Mounted Vacancy Sensor, White Automatically turns light on and off based on room's occupancy No external power packs, power wiring, or communication wiring necessary Has a radio frequency (RF) range of up to 60ft between sensor and compatible Lutron RF controls like Maestro Wireless (MRF2-) dimmers and switches 10 year battery life 360 field of view, 400 sq. ft. range at 9 ft. ceiling height