Crestron Green Light sensors deliver a powerful and cost-effective solution for reducing energy costs and enhancing the functionality of lighting and environmental systems. The GLS-ODT-C-500 is a low-profile ceiling mount occupancy sensor designed for smaller areas up to 500 sq. ft to detect when the room is occupied. Advanced self-adaptive, dual-technology motion sensing affords extreme reliability for control of lighting, climate control and other devices in the room. Dual-Technology Occupancy Sensing. Achieving consistent and dependable occupancy sensing is accomplished using a combination of ultrasonic and passive infrared technologies. Ultrasonic motion detection achieves high sensitivity to small movements over a large area, while passive infrared ensures superior immunity to false triggering from air currents, inanimate objects, or movement in an adjacent corridor. The GLS-ODT-C-500 allows independent sensitivity adjustment of each sensor type for optimum performance in any space.