This is a set of two J&T Long Exhaust Manifold Springs, and are intended for use with 1/8 Scale Nitro Engines. The Exhaust Manifold Springs attach the tuned pipe manifold to the engine exhaust port. With the manifold springs wrapping around the engine, over time they tend to lose their resiliency as they absorb the intense heat from the engine. As this happens, the manifold springs weaken and become vulnerable to breaking which can lead to manifold gasket damage; and in the worst case, engine damage.