Unfortunately, I wish I could add to the positive reviews. I purchased a complete Boundary system with 2 sirens, 6 PIRs, 7 contact sensors and multiple fobs. Love the hub and sirens, although wish the latter could be mains connected. The sensors seem oversized in todays technological age but worst of all is the system is just so flakey. Connection range is quite appalling and I am forever getting notifications of sensors and sirens going off line, sensors don't update the app in real time and alerts on the hub being unable to be cleared and hence being unable to set the alarm with assurance. I am working with tech support, who are very helpful, to resolve continuing, frustrating issues but doing so via email, while reasonably responsive (between 9-5, M-F only), is just so time consuming. Weeks in thus far and still not got a fully operating system. Unlike my last system, Eufy of all brands, which NEVER faltered but no outdoor sirens :( , and Visonic before that which also NEVER faltered (but no app), this is a completely different story. I am now pretty committed as I have attached sensors to walls and doors/windows using screws so feel I have little option but to continue this journey. However, with sensors and sirens continually dropping connection, and constant ZWave & WiFi disconnection notices, I am unsure that I have much faith in this system. Contact and PIR sensors are twice the size of the other brand yet have appalling range, despite being sent a range extender by Boundary. Whilst I would not, at this stage at least, say do not buy this system, I wold say do so with a very open mind and a possible long road ahead to get a fully working system. I'm now off to arrange return of a contact sensor which simply refuses to pair with the system. Just another fault :(