MFJ-8504NB lets you hook up to four SDR radios, shortwave receivers or transceivers to two receive antennas! The AM notch filter prevents noise from strong broadcast stations. This lets you monitor several signals at once -- an amazing receiving post! This broadbanded radio multi-coupler has excellent performance from 300 kHz to above 850 MHz, 30dB IP3. Reverse polarity protection, internal fuse, BNC input/output. Unused ports automatically terminated. Rugged, fully shielded aluminum, 6Wx13/4Hx33/4D in. Use 9-15 VDC@150 mAnominal or 110 VAC with MFJ-1312D.