love this product
Best range I could get was maybe 75 feet, One of the sounders stopped working a week later
This is an initial review - Ill update once I have some use experience with the sensor. The main reason I am posting is so that if you are going to go the route of not using batteries that you get the correct USB setup. SadoTech and Amazon both erroneously state that this unit takes a mini adapter - it does NOT, repeat NOT. The sensor is outfitted with a female MICRO B and will require a USB with a male MICRO B end ( fits many phones and Kindles). Knowing that there are many types of USB cables I even did a live chat on the Sado Tech site and was told by a rep that I needed a mini but they did not know which version mini - great!. I wanted a USB with a right angle so I purchased from Amazon a USB A to MINI B right angle and low and behold it isnt even close so I checked some cables I have on hand, my Kindle and Sanyo phone cable fit. I checked a Wikipedia article on USB cables and determined that these are MICRO B cables. Ill post an update on use of this sensor in an unheated garage once I have some experience with it.
Works well for me as long as its not too cold. I mounted it over a hidden rear door outside but protected from rain. When the temperature drops too low it goes off constantly and I have to remove it so it clearly can not tolerate low temperatures. Did not record what temp that started at, probably around 40F
love it. wish it were waterproof