Vintage Used Polarad 160 MHz Low Pass Filter. BNC connectors on input and output. FL101 from military test equipment UPM-84. About 7 inches long, 0.5 inches diameter. Serial number 108. 2 db insertion loss from 100 to 250 MHz, down 9dB at 400 MHz and 20 dB at 500 MHz. See paragraph 6-30 in the online UPM-84 manual.