Par Electronics VHFDN153MAR tuneable VHF notch filter/intermod filter. 45 DB 1 mhz bandwidth notch filter. Compact in size. Body of unit measures 2" X 2.5" X 1" deep. Unit comes tuned to notch 152 to 153 mhz but can be retuned to any frequency from 150 to 170 mhz. SO239 connectors.