Powerbomb Stainless Steel Header. The redesigned PowerBomb is a four-stroke header that incorporates FMF's patented PowerBomb module at a precise location in the initial stage of the header. By positioning this "Bomb" at a key point in the system, increased performance and flow is achieved through the expansion and contraction of exhaust sonics through the system. The result is a flow increase of nearly 10%! The outer chamber in the PowerBomb allows the air to expand, cool and ramp back up at a higher velocity. Additionally, the PowerBomb is a "pre-muffler" of sorts which helps to lower the bike's sound output by providing more sound absorbing surface area for the sound medium (exhaust gases). Tuned for bottom to mid performance. PowerBomb headers are the front runner in performance headers. Designed for full service access to oil filter. Detailed Specifications: Type: Header.