The HP / Agilent 5351A Microwave Counter measures frequency from 10 Hz to 26.5 GHz with input sensitivity of -40 dBm up to 12.4 GHz,and -28 dBm up to 26.5 GHz. The 5351A offers selectable resolution form 1 Hz to 1 MHz with an 11 digit resolution backlit LCD display. Additional 5351A Features: self-check, diagnostics, display and keyboard lockout, overload indicator, HP-IB learn mode.