The OHP 55-9 from Beijing Ocean Microwave Corporation is a RF High Pass Filter with Frequency 55 to 800 MHz, Insertion Loss 0.32 to 0.37 dB, Rejection 40 @ 28.6 MHz to 60 @ DC to 21.5 MHz, VSWR 1.23:1, 1.50:1, Return Loss 14 to 20 dB. Tags: Module with Connectors, Chebyshev. More details for OHP 55-9 can be seen below.