These Band 5 Channel A and B filters from Wilson Pro block strong interfering cellular network signals to avoid overloading the amplifier unit. Channelized filters allow highly target booster amplification for carriers and bands that need maximum signal improvement.
The FCC limits the maximum permissible gain of signal booster units, to prevent amplifiers from interfering with the wider cell network. Sometimes, a customer on Network X might find that the nearby cell tower of Network Y is overpowering the booster unit, limiting or even overloading the unit's gain and so preventing it from maximizing the gain from the weaker Network X.
These filters are available to block Channel A or Channel B, and for both 50 ohm (N connector) and 75 ohm (F connector) systems.