Sennheiser ASP 212 Passive 2 x 2-Way Antenna Splitter

True diversity needs two antennas, and two receivers sharing one pair need a splitter that keeps the A and B paths separate. That is exactly what the ASP 212 does: two independent 1-to-2 splits in one 139 x 98 x 53 mm block, so two diversity receivers work off a single antenna pair without the paths ever meeting.

It is passive, so there is nothing to power and nothing to fail, and it weighs 220 g. On short antenna runs the split loss is a fair trade for the cabling it saves. For larger racks, the ASA 3000-US does the same job actively, 2 x 1:8 with booster power on every port.