Milltrip PIR Motion Sensor Downlight ,Round Flush Mounted Ceiling Light,12W AC85-265V LED Ceiling Light Downlight Human Body Sensor Recessed Lamp for Home Indoor Pure White/Warm White(White) - Amazon.com
Source Mini Flush Mounted PIR Sensor Indoor, ceiling mounting for installation, infrared motion sensor range 6m / 360 degree on m.alibaba.com
Recessed PIR Sensors - Electrical 4 Less
Honeywell 995 - PIR Flush Mount Motion Detector - Alarm Grid
The DANLERS range of passive infra-red occupancy switches