We have had a few of these sounders start coming up with problems, usually after a battery change. Its quite annoying as customers dont want to pay for the battery replacement and the sounder replacement. I do understand why but it means we are left with Visonic battery that we may not use and theyre not cheap. The early wireless systems were rubbish, the Visonic, Gardtec, and Pyronix, offerings were better, but not by much. Im not a big fan of wireless but the wireless stuff thats out there now is so much better.