4-Mile Range MURS Driveway Alarm w/ Hand Held Radio Longest wireless driveway alarm range of 4 miles Compatiable with probe sensor and with hand-held radio 80 ft detection range from sensor. Microprocessor code-learning technology eliminates false alarms, receiver responds only to motion sensors assigned to it. Receiver can double as an intercom if you have two receivers Portable receiver, operates on rechargeable batteries