I've got Glider Tug project and wanted to install an air filter on the back of my carburetor. I came across this one made for Husqvarna Chainsaws that looks like it'll work pretty well on just about any small gas engine. I'm in Florida and if you've every been here you know that the entire state is made of sand...

It measures 3.5 inches square by about 1.5 inches thick and weighs 2.8 oz with the clamp.

It should fit most motor boxes or behind the firewall on most models.

The part number is 503 55 11-01 "Filter"
and 503 56 00-03 for the "clamp".

This is the (Air Filter Heavy Duty) for Husqvarna's 59cc to 70cc engines so I'm thinking it should have plenty of volume for most of our model airplanes.

If you hunt down the part number/parts list they've got a carb to filter manifold that should readily adapt to a Walbro type carburetor.

I've got a lathe so I'm going to machine an adapter out of Delrin.

Anyway, Just a heads up if your looking for an air box/filter....