The CSM-20M-3G from Crane Aerospace & Electronics is a Directional Coupler with Frequency 2000 to 4000 MHz, Coupling 20 dB, Coupling Variation ±1.25 dB, Frequency Sensitivity ±0.75 dB, Directivity 22 dB. Tags: Module with Connectors. More details for CSM-20M-3G can be seen below.