Features: 1 VSWR. Forward power direct digital readout, without any calibration. 2. Maximum measurable power range up to 100W. 3. 3 seconds check your antenna SWR , also check your radio RF power watt.4.Easy to install handheld Radio Specifications: Measurable power range: 0.1-100W Maximum power: 100W Accuracy: mean + / - 5% * Not for the DMR digital radio. Specifications: MAX. Power in 100 WATT V.S.W.R 1.00~19.99 Frequency Range COVER:125MHz~525MHz Insertion Loss < 0.15dB(VHF) , < 0.25dB(UHF) Temperature 0℃~70℃ Battery Build -in Li-ion Battery Size(WHIT OUT SMA 25*25*60 (mm) Power in 5V (micro usb) Interface (in and out ) SMA female Impedance: 50Ω Weight 160g Features function Push red button and hol 3 sec.to" Power on " and "SWR "mode " Led display shows: Push red button -" Power Meter "mode , Led display shows:Push red button -" SWR "mode ,Led display shows: Push red button and HOLD -" POWER OFF 1.1How to use Power meter .Push red button -switch onPush red button at once to mode "POWER meter " ,Led display shows: Connect the SMA (mark TX) to Radio output .Connect the SMA to DUMMUY Load Caution : Please use correct dummy load , High power will damage the dummy load. 1.2How to use SWR meter .Push red button -" Power on " and "SWR "modeDisplay shows: Connect the SMA (mark TX) to Radio output .Connect the SMA to ANTENNA When the the led show 1.00 to 1.50 , mean the antenna is suit the frequency, When the the led show 1.50 to 3.00 , mean the antenna is not good suit the frequency, When the the led show up to 5.0 to 19.99 , mean the antenna is not suit the frequency. Package Contents 1x Power Meter PM-100W 1x English User Manual 1x USB charger cable 1x USB AC adapter 100-240V PM-100W User Manual