Muffler kit for the Camp Power 2800 and 2500 Onan Generators The 699-01185 muffler kit uses an approved flexible tube section between the manifold and muffler. It is designed for use in travel trailers, short body truck campers or any application where the position of the muffler in kit 541-0618 interferes with bumpers, floors, skirts, brackets or chassis rails.