Rotary vane compressors have two internal air filters. Air filter elements are included in repair kits or can be purchased separately. Black plug that holds filter does not come in repair kit. All models use the same plugs and filters.
RVBF Internal filter
IAF25F Replacement filter element
IAF38F Replacement filter element
IAF25 Replacement Air Filter 1/4 in. mpt
IAF38 Replacement Air Filter 3/8 in. mpt