Our special Active Differential Probe ADP1 for the SPECTRAN NF-5030 Spectrum Analyzer offers a potential free measurement and also expands the measurement range up to 240V. With this probe, the signal will not be influenced (potential free measurement). It also protects the SPECTRAN Spectrum Analyzer input against high voltages up to 1400V (CAT3). It's a "must have" for direct cable measurements on DSL, ADSL, VDSL, free-running oscillators, mains, etc. Included with delivery is a special grounding kit that protects the unit against static electricity (ESD). This is very important for long-time measurements. The power supply is possible with the internal cells (4 x AA, not included) or, at long time measurements, with the included mains adapter.