For sale, this is a new Keysight / Agilent 34906A 2 GHz Dual 1:4 RF Mux, 75 Ohm Module for 34970A/34972A.
This is a sealed product in factory package. Unit is being sold as pictured with the cable interfaces. No other accessories included.

HIGHLIGHTS
Dual 4 Channel RF Multiplexer
2 GHz bandwidth, 75 Ohm
Cascade together for up to 16:1 multiplexer
BNC to SMB adapter cables included
The Keysight 34906A RF multiplexer module for the 34970A/34972A Data Acquisition/Switch Unit offers broadband switching capabilities for high-frequency and pulsed signals. Use it to route test signals between your device under test and your signal generator, oscilloscope, spectrum analyzer, or other instrumentation. The RF multiplexers are arranged as two independent 1 x 4 multiplexers, each with a common shield and a switched center conductor. Connections can be made directly to SMB inputs with 2 GHz usable bandwidth, or to the BNC-to-SMB adapters provided with 1 bandwidth.

Product Information