FMF Racing 43289 Header: Automotive. Buy FMF Racing 43289 Header: Headers & Mid-Pipes - ✓ FREE DELIVERY possible on eligible purchases. Manufacturers part number: 043289 . The PowerBomb Is a Four-Stroke Header That Incorporates 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. Result Is a Flow Increase of Nearly 0%! 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 s to Lower the Bikes Sound Output by Providing More Sound Absorbing Surface Area for the Sound Medium (Exhaust Gases)..Please Note: The Image Displayed Is Representative of the Item, but May Vary Slightly Depending on Your Specific Model.. . . .