Kenwood ProTalk&reg; TK-2300V4P 4 Channel model VHF 2 Watt Portable Business Radio, 27 VHF Pre-Programmed Frequencies Up to 250,000 sq.ft. In Steel and/or Concrete Reinforced Buildings Up to 20 Floors In High-rise Buildings Up to 1.5 miles Residential Areas (near buildings) Calling Alert, Internal Vox/Hands Free Ready Voice Inversion Scrambler by Channel