Audio-Technica ATW-SC410 UHF Passive Splitter/Combiner

The ATW-SC410 does one job with no fuss: split a single antenna signal to feed two receivers, or combine two antenna feeds into one, over the full 470-990 MHz UHF wideband range. It's fully passive, so there's no power supply or configuration menu involved, just BNC-type connectors and a 2 dB typical insertion loss to budget for in the signal chain.

It still passes DC through the connection, up to 420 mA, so an antenna or booster on either end of the run keeps getting powered even with the splitter in between. It's sold as a pair, sized right for a two-antenna diversity system that needs to add a second receiver without pulling new antenna cable.