The CSC-30-4.2G SQ from Crane Aerospace & Electronics is a Directional Coupler with Frequency 3900 to 4500 MHz, Coupling 30 dB, Coupling Variation ±1 dB, Frequency Sensitivity ±0.2 dB, Directivity 16 dB. Tags: Module with Connectors. More details for CSC-30-4.2G SQ can be seen below.