how much do home alarm systems cost
The feedback on the SA511B is even better, albeit more limited: 4. 7 stars at Amazon, 4. 6 stars at Home Depot, but that's only based on around 20 reviews across the two sites. The First Alert SA521CN 3ST Est. $40 is a hardwired version of the battery operated First Alert SA511CN2 3ST/SA511B interconnectable smoke detector. The two First Alert smoke detectors can be mixed and matched to create a smoke detector network that covers your premises.