Wireless Intercom 2-Way, Band Type UHF, Material Polycarbonate, Channels 1, Output Watts 700 mW, Width (In.) 5 in, Height (In.) 7 in, Length (In.) 3 in, 114 Programmable Channels, 154, No External Channel Select, Battery (3) D Alkaline Batteries, Provides Up to 5000 Transmissions, Operating Range Up to 2 Miles, Includes Built-In Remote Control Relay for Access Control, Concealed Vandal-Proof Antenna, Mounting Brackets, Requires Matching 2-Way Radio