Dual stage foam element increases dust holding capacity
It’s a proven filter. Brackett Air Filters (formerly AC) have been in service on aircraft and helicopters since 1968. At present, Brackett Foam Filters are installed as Factory original equipment on 16 current production aircraft and four helicopters.

Foam Filter is unaffected by water (approved for sea planes). It has no pleats to store dirt and is abrasive resistant.
The cut-a-way shows the exclusive Brackett filter frame safety features.