LevelOne Racing slip-on & bolt-on exhaust systems provide increased power and torque, and extreme weight savings and a deep race inspired rumble that is maintained throughout the full r.p.m. range. The entire exhaust internal core is maintained at 2.25" (57.15mm) with a .035" (.88mm) wall thickness. The stainless steel finish, TIG welded race lip and build quality make the LevelOne Racing exhaust the system of choice. Fits the Following Bikes: Honda CBR600 F4i (01-07)