The maximum communication range between Skylink security sensors and security accessories is listed at 300 feet. However, there are several factors such as walls and radio frequency (RF) interference that can significantly reduce this distance. Don't take a chance at letting your alert system fail when you need it most, use the Household Alert Wireless Repeater to Extend the communication range between the Skylink wireless devices and ensure the security of your home. This product requires the use of a 9 Volt battery or plug-in power adapter, each are included. Hands-on Research Started testing by using a door/window contact and a receiver. Moved the two products further and further apart until I reached a point where the transmitter and receiver would no longer communicate. I then put the Household Alert Wireless Repeater between the receiver and the transmitter and the products resumed communication. It was also able to extend the total range between the products as I could then move the receiver and transmitter further apart.