I installed them and they work great.

I must say that the alarm company really sucks. I asked them to install pet safe sensors - which they didn't. I asked them twice to to replace the sonsors - which they didn't.
I also asked them to wire in the garagge back door which already had a mag sensor. They were in the roof and did their tests etc. I turned the alarm on one night and when I turned the alarm off in the morning I saw that the back door was still wide open. The f...krs never wired the door in. I will sort this out myself as well. Why is it that companies just don't give a fxck about their service delivery - one would think that an alarm company would actually do a proper job in the first place. I don't think that this is a South African thing, my wife, who is in the UK at the moment, told me about the terrible service they get there too.