ADSBexchange 1090 Mhz SAW filter in a blue aluminum case. Insert this between your antenna and receiver if you are experiencing interference from local RF signals.
Note, this only passes 1090Mhz ADS-B signals, not 978.
Only needed if you have local RF interference, commonly caused by mobile phone towers or other sources.
Also available on Amazon Prime here: https://www.amazon.com/dp/B09RPKHQ6S