This item replaces a sensor we had installed for several years at a different house. The sensor eventually became corroded and no longer worked. We have always been pleased with the whole alarm system,  but now at our new house it is not functioning properly. It appears that the signal cannot get in through the house although the receiver is placed on a windowsill in a direct line of sight to the sensor. The alarm works fine if the receiver is moved a few feet over into the garage,  but it cannot be heard in the house. At the time of this review,  the problem has not been resolved.