The E2695A is an accessory probe head that plugs into the InfiniiMax 1130 series of probe amplifiers to allow differential SMA connections to a single channel of the oscilloscope.
If you need to connect SMA cables (vs. a probe) to the oscilloscope, the E2695A offers the following:
Connection to SMA fixtured differential pairs
Semi-rigid coax to change span between SMA connectors