Dosy CB Ham Radio SWR Watt Meter TC-4001P Test center Reads RMS and Peak Power Four Watt Ranges: 0 - 20, 0 - 200, 0 - 2000 and 0 - 4000 Measures Modulation Percentage Built-in phone jack for signal monitoring Headphones AC/DC Power Supply Reads RMS and Peak Power, Measures Modulation Percentage, Measures Antenna SWR, Measures SSB Modulation, DOSY Professional Architecture, Built-in phone jack for signal monitoring Headphones, AC/DC Power Supply, Large 4 1/2 inch Back lit Meter, Four Watt Ranges: 0 - 20, 0 - 200, 0 - 2000 and 0 - 4000