This is a big block air filter cup made to outperform the stock air box by far. With this you are able to add an aftermarket standard 2 7/16 air filter to increase the airflow dramatically! Application: gx390, gx340, 420cc Clone. This new model replaces the old aluminum ones; this one being made out of a high quality nylon making it super light weight!
This air filter adapter will fit and was designed for the Predator 420cc engines with no modifications.
*Please Note: The air filter adapter will not fit a duromax 420cc without modification to carburetor supports