Genuine Briggs and Stratton Air Filter for 20hp, 21hp, 22hp and 23hp air cooled Briggs and Stratton V twin carburettor engines.

Fits:

Later Spitfire 4.0

Boxxer 421

Later Phoenix 450i

Phoenix 450 DD and DD+ carburettor versions

The Phoenix 450 Efi uses air filter part number 394018S