Bosch Wireless Motion Sensor ISW-ZPR1-WP13

I have recently purchased 3 of these sensors from amazon for $14 each and it was hard at first to get them to connect, but i stumbled upon this article that made it easy Click Here.
just keep in mind that when setting them up they first goes into pair mode then after pairing it turns on walk mode and you will see a visible light when motion is detected, after no motion for 90 seconds it goes to armed mode, and that means it will report motion and sit in standby for 3 min till it will arm itself again to reduce RF and save battery and you will not see any light.

I had 2 of three fail within 6 months. Maybe you’ll have better luck.