The one you see in the first post in this thread is what I have:
I ordered mine from WalMart. Was supposed to be a three-pack of that sensor, but I got two and then a third different sensor w/no cable. I complained and WalMart refunded me so I ended up happy. 
I even extended the cable on one in my attic so I could run the sensor waaaay into my attic to reach a steam shower generator unit, and allow me to keep the base unit right by the attic access so battery changes are easy. Used this cable:
https://www.amazon.com/gp/product/B01FQS6B8A/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1
