it would be nice if each unit had a different sound so you would know which area movement is coming from.

I got this because the coyotes are roaming the yard year round. They took out the neighbors cat and I don't want them attacking my dog.

Now when they make their presence known on the game trail out back I have enough time to whack em.

Some people seem to have the wrong idea about what this is. It's not really a outdoor driveway alert nor is it an indoor alarm system. It is an indoor motion alerter. It makes a noise when it senses motion. Think like a doorbell chime. That is it. You cannot use it outdoors and it does not have threatening tones to scare away burglars-- just door chime type tones.

I got this because I live in an apartment and some guy tried to break in my window months ago. I already have cameras and guns but wanted something to wake me up if someone breaks in my door while I am sleeping. This is day 1 of having this but so far I have been pleasantly surprised! I placed one sensor at my back door and another in my living room. It's a distance of probably about 50-75 feet and through 2-3 walls and doors. Surprisingly it works very very well so far! It is loud enough where it should be able to wake me up at night. I do have it plugged in near the floor (lack of other outlets) so I am worried about it possibly waking up the downstairs apartment neighbors when I get up to use the bathroom at night but I will have to sort that out later.

Minus one star for the mounting hardware being a bit on the cheap side. However it does still mount just fine and is adequate. Also I should note this seems to be a generic setup from China. I notice many different brand names/sellers for this on Amazon which appear to be the same components. I will update the review if anything bad happens so no news is good news!

I just got these so can't rate battery life I needed something simple and portable, didn't want to rely on WiFi or Bluetooth. I don't need a picture, just need to get an alert when someone is on the move.

Installation couldn't be easier. I'm just setting my sensors on tabletops so that I can move them as needed, they can even go on the road when needed. I saw one review with a video showing floppy ball joints, mine are not like that and easily hold position. They are very easy to position as a stand for tabletop use. The sensors are sufficiently sensitive and position is not especially critical, it didn't take any fine tuning to make them work.

I can be a little critical of the receiver controls and functions, but not enough to ding stars in the ratings. The mute works great, which is necessary. Volume is a little sketchy, loud, sort of loud and tolerable. I wish the low volume was much lower.

My biggest complaint is the 38 "chime" options. One might think that with 38 options at least one would be some kind of soft wind chime sound, or other soothing chime. In my opinion, every sound is loud, harsh and annoying. I found one I can tolerate at the lowest volume. Both volume and sound choice are made by cycling through the options, and it resets when unplugged so if you are moving the receiver from one location to another as I do you have to reset volume and sound choice each time. And it's sort of a noisy process that could easily annoy others. So if I want to move the receiver into my bedroom at night and my husband is already sleeping there is no way to reset without waking him. I can mute it, count the clicks, unmute, and hope I get it right. That's the best solution I can think of.

So, really, it is not perfect, but it is going to do the job I need done and the price is very reasonable and it didn't take me all day to set it up.

Easy set up... Very very sensitive to ANY and ALL movement