The 4161-20 from Narda-MITEQ is a Directional Coupler with Frequency 1.7 to 2.1 GHz, Coupling 20 dB, Coupling Variation ±1 dB, Frequency Sensitivity ±0.30 dB, Directivity 20 dB. Tags: Module with Connectors. More details for 4161-20 can be seen below.