Frequency Range: 5 Hz to 500 MHz High Input Impedance 100kOhm, 3pF Used for both spectrum and network analyzers Protective sleeve to prevent ESD and physical damage to probe tip The Agilent 41800A Active Probe probe offers high input impedance from 5 Hz to 500 MHz. It works with many Agilent spectrum analyzers to evaluate the quality of circuits by measuring spurious level, harmonics, and noise. Low input capacitance offers probing with negligible circuit loading for precise, in-circuit measurements of audio, video, HF and VHF bands.