The RFS-B 0.3-3 is a passive magnetic field scanner probe. The probe head is basically constructed as for the RF-B 3-2. Field lines from other sources entering the probe head laterally are not detected. Because of its very small design, it can be used for measurements at hard to reach spots ,e.g. between components. It has a current attenuating sheath and its upper side is electrically shielded. It can be connected to a spectrum analyzer or an oscilloscope with a 50 Ω input. The H-field probe does not have an internal terminating resistance of 50 Ω.