The 251-017-020 from Broadwave Technologies is a Directional Coupler with Frequency 2000 to 4000 MHz, Coupling 20 dB, Coupling Variation ± 1.25 dB, Frequency Sensitivity ± 0.75 dB, Directivity 20 dB. Tags: Module with Connectors. More details for 251-017-020 can be seen below.