The OHP 50-4 from Beijing Ocean Microwave Corporation is a RF High Pass Filter with Frequency 50 MHz to 1.25 GHz, Insertion Loss 0.51 to 0.65 dB, Rejection 40 @ 32.3 MHz to 60 @ DC to 26, 3 MHz, VSWR 1.23:1, 1.50:1, Return Loss 14 to 20 dB. Tags: Module with Connectors, Chebyshev. More details for OHP 50-4 can be seen below.