This is a pack of 12 Diffuser Discs for the SuperTrapp 3S Series Spark Arrestor Mufflers (sold separately). Typical installations should use 1 disc per 3 horsepower for proper back pressure. This 12-pack is enough for engines up to 36 HP, or smaller engines running below 2400 RPM or running an additional muffler. Using fewer discs will further reduce noise but will also cause some power loss.
SuperTrapp mufflers are the only USDA Forest Service Approved spark arrestors that do not rely on restrictive swirl baffles or fragile screens. Sparks are funnelled into a collection chamber in the end cap, while exhaust gases exit between special diffuser discs. Even if the collection chamber filled to capacity, the small 0.023" gap between the discs still provides a back-up layer of spark protection.
We also offer a smaller 3-Pack of 3 inch Diffuser Discs, Part No. ST-3S-6503. The smaller pack is enough for engines up to 10 HP running over 2400 RPM.