The D4-50001 from Crane Aerospace & Electronics is a Bi-Directional Coupler with Frequency 10 to 1000 MHz, Coupling 20.25 dB, Coupling Variation ±0.5 dB, Power 3 W, Insertion Loss 0.75 dB. Tags: Module with Connectors. More details for D4-50001 can be seen below.