Well, after a couple of years, my Model B belt bit the dust while on its first run of SS pin tumbling. I bought the Home Depot o ring. It started slipping within a few minutes. i did find another substitute though. I have an '08 Tundra with 5.7 l engine. The oil filters from Toyota come with a new o ring. I keep one extra for grins. Just so happens it fits the Thumbler's Tumbler Model B. It's larger in cross section than the Home Depot o ring, and seems to be working for the time being. We'll see how it lasts. No risk since I get one every 5,000 miles, and the filter element with o ring is only $5.00