Z-Wave Plus PIR Motion Detector with Temperature Sensor, NO LOGO $20 +FS
I couldn't find any valid coupon codes, but $20 doesn't seem bad for these. Reviewers say you can turn down the sensitivity for pets, but it isn't well documented. Free shipping. The only downside I can see is they are huge (according to Q&A - 61.7 x 83.6 x 50 / 38.5 mm (width x height x depth top / bottom)
2.4 x 3.3 x 2 / 1.5 in).