No - these are really good filters. You just bolt them onto eBay - punters go in one end and money comes out the other! I bought a WDG3L petrol tank like that - it was surely full of gold sovereigns for the price I paid, but I have not had one out of the damn thing yet.............
If you ever need a NOS vokes filter try aussie ebay.One just sold for $500.There must be a warehouse full of them somewhere.I think they were sent out here when the aussie army requested some sort of filter for their bikes.Thing is all M20's sent out here had the full petrol tanks with no cutout.Sam.