The E503 from Microwave Engineering Corporation is a 90 Degree Hybrid Coupler with Frequency 2 to 4 GHz, Average Power 50 to 400 W, Peak Power 1 kW, Isolation 18 to 23 dB, Coupling 3.3 dB. Tags: Module with Connectors, Octave Band. More details for E503 can be seen below.