Note: The green light is on when VSWR is less than 1.5, the yellow light is on when VSWR is greater than 1.5 and less than 2.5, and the red light is on when VSWR is greater than 2.5. If the VSWR is greater than 2.5 less than 3, the buzzer will alarm intermittently, if the VSWR is greater than 3, (aisanray) will alarm continuously. Battery undervoltage, the buzzer will keep prompting and the yellow indicator light will be on. The buzzer can be turned off with one key Specification: Item Type: Standing Wave Meter_x000D_Material: Aluminum Alloy_x000D_Color: Black_x000D_Battery: Polymer Lithium ion Battery 503450 (Built in) Capacity: 1000mAh_x000D_Charging Interface: Type C_x000D_Frequency Range: 1.8MHz-50MHz (Actually Has Reference Value for V band)_x000D_Power Range: 0.5w-120w (up to 200w, Below 120w Long Term Test Recommended FM, AM, CW Mode, SSB Mode Optional)_x000D_Measurement Accuracy: