The 4243B-10 from Narda-MITEQ is a Directional Coupler with Frequency 1 to 3.5 GHz, Coupling 10 dB, Coupling Variation ±1 dB, Frequency Sensitivity ±0.5 dB, Directivity 23 dB. Tags: Module with Connectors. More details for 4243B-10 can be seen below.