Moose also makes a GasGas air filter, part # M761-20-43
states it is for GasGas 125/200/250/300 97-07. This is the filter I have been using and it fits fine.
Does the rubber grommet in the twin air fit the cage snugly?I purchased a uni filter last season for a honda cr and the grommet is larger than my cage where the bolt goes through (on the inside) Cant remember what year uni I purchased but I'm thinkink of ordering a stock gas gas filter so I KNOW it will fit proper.05' DE 300
On both my 04 an 06 300's I have always used the No Toil Gas Gas spicific filters and the fit is very good, along with durability. I do use No Toil filter oil and its cleaner so I'm not sure how they hold up to solvents and different brands of filter oil.
I have one of those as well. Good quality filter, but the fit seems a little bigger on the cage. When I install it I leave it a little loose at first and take extra care to be sure the foam ring is under the cage all the way around. I use No-Toil as well and both their filters and Twin Air have been fine for many cleanings/oilings.