I chose a company named “Guardline”. They have a web site. Check them out. I purchased the home receiver and two alarms, one on the driveway and another positioned behind the house. One does a “ding dong”, notifying us that its the driveway and the other emits a cricket sound to denote the sensor located in the woods behind the house. One sensor was defective and we returned it. Guard line provided us a new sensor to replace the defective one. So far, I’ve been pleased with the system.
