The compact built of the PML 311 with a diameter of 2.5 mm at the Probe Tip facilitates measurements in dense SMD circuits, because of the good visibility of the device under test its small body provides.
The low input capacitance loads the measuring point with only 9.5 pF. Less load is only achieved by active probes.
Especially when measuring signals with fast risetimes the adaptation of the probe towards the measuring point becomes crucial to the results. But long connections add inductions and resonances to the signal, hence falsifying them.
To counter this phenomenon PML probes are shipped with a PCB Adapter and an IC contacting system for probes having a 2.5 mm housing.