Specifications: Measurable power range: 0.1-100W Maximum power: 100W Accuracy: mean + / - 5% ***notice ***Not for the DMR digital radio*** MAX. Power in 100 WATT Frequency Range :125MHz~525MHz Insertion Loss < 0.15dB(VHF) , < 0.25dB(UHF) Temperature 0℃~70℃ Battery Build -in Li-ion Battery Power in 5V (micro usb) Interface (in and out ) SMA female Impedance: 50Ω Size(WHIT OUT SMA 25*25*60 (mm) Weight 160g V.S.W.R range 1.00~19.99 Features function: Press red button and hol 3 sec.to" Power on " and "SWR "mode " Led indicat Press red button -" Power Meter "mode , Led indicat Press red button -" SWR "mode ,Led indicat Press red button and HOLD -" POWER OFF 1.1 How to use Power meter . Press red button -switch on Press red button again to mode "POWER meter " ,Led Indicat Connect the SMA (mark TX) to Radio output . Connect the SMA to DUMMUY Load ***Caution : Please use correct power of dummy load , High power will damage the dummy load***. 1.2 How to use SWR meter . Press red button -" Power on " and "SWR "mode Indicat Connect the SMA (mark TX) to Radio output . Connect the SMA to ANTENNA Result explaint: 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 SW-33 markII SWR/POWER METER 1x English User Manual 1x USB charger cable 1x USB AC adapter 100-240V  1x SMA male to SMA male Adaptor (***dummy load/ extra antenna adaptor optional***)