Baby Alert USA reviews?

J
I was wondering if anyone has ever used the Baby Alert USA. It is a device to help prevent a baby/child from being left in a car. I want it as a precautionary device. I do not intend to ever leave my baby or child in the car but things happen and I'm ok with having a device to help protect my child. No rude comments please, just reviews. 
http://babyalertusa.com/child-minder/childminder-softclipr-system-2-system-package.html