The DTK-VSPN surge protector combines state-of-the-art hybrid circuit technology with N type connectors to protect a variety of coaxial devices. Cellular alarm communicators are becoming more widely used in the fire alarm industry. In many installations an external antenna kit is added to attain the required wireless signal strength. Since the antenna is external to the building, it becomes an avenue for harmful transient surges to enter the fire alarm system through the coaxial antenna cable.