The OHP 650-4 from Beijing Ocean Microwave Corporation is a RF High Pass Filter with Frequency 650 MHz to 4 GHz, Insertion Loss 0.42 to 0.45 dB, Rejection 40 @ 419 MHz to 60 @ DC to 341 MHz, VSWR 1.23:1, 1.50:1, Return Loss 14 to 20 dB. Tags: Module with Connectors, Chebyshev. More details for OHP 650-4 can be seen below.