Gast External Filters Fits Model AT05.
Over time the filter from cleaning will degrade and need to be replaced.
The filter is important as it keeps dust and dirt from entering the compressor/vacuum pump.
Dust and dirt remove the film that is produced by the carbon vanes that allow them to run for so long.
Gast felt filter B344A for AT05.
P/N: 9U-C4Y9-ZFA6
