I bought some from bassett about 6 years ago for 2.5'' zoomies. they are or at least were when i bought them very cheaply made just some thin sheetmetal wrapped around the inner baffel with some fiberglass stuffed in between it. they must be run with water injected zoomies or they will burn up. even running water they dont last long at all. I would be looking at my motor when i would start it and sometimes when it would fire you could see little chunks of baffel go shooting out into the lake. they are kinda expensive to buy just to have them get trashed very quickly. the guy that sold them to me from bassett even says NO GUARANTEE! that they will last or that they will keep you from getting a ticket. but that was 6 years ago it might be different now.