The Sennheiser AM 2 is used with the GA2 Evolution Series rackmount kit to relocate the two antennas from the back of a rackmounted receiver to the front of the rack. It is compatible with EW G2/G3/G4 and EW-D receivers as well as SR 300 IEM transmitters.
The AM 2 comes with two 50-ohm BNC cables and mounting hardware.
Works fine but why this doesn't come with the wireless unit is a mystery. The unit has everything you need for rack mounting except these cables.
I mounted the (four) antennas for a pair of wireless mic receivers on the rear of a 6U short (effects) rack-mount travel case--rather than just leave the antennas on the wireless receiver buried inside the case with all the internal & external cables for the mic receiver pair (1U), line compressors (2x1U), and mic mixer (3U).