1.8MHz-50MHz 0.5W-120W SWR HF Short Wave Standing Wave Meter SWR and Power Meter
Frequency range: 1.8mhz-50mhz. Standing wave range: 1.0-99.99. If the standing wave is greater than 3.0, the buzzer will keep prompting. Charging shows red light, full green light and yellow light when working.