The D4-40004_5 from Crane Aerospace & Electronics is a Bi-Directional Coupler with Frequency 10 to 500 MHz, Coupling 20.25 dB, Coupling Variation ±0.35 dB, Power 3 W, Insertion Loss 0.5 dB. Tags: Module with Connectors. More details for D4-40004_5 can be seen below.