Fab Pros V-band Flange and Clamp set for the Turbine Exit (Downpipe side) on all the T4 flanged 200 and 300 Series Turbos, S, SX, and SX-E with the beveled face. This is the 4.21" 3/4 Marmon Oulet V-band flange compatible with these BW (Borg Warner) Turbo models including: Borg Warner S200 S200-SXE S300 S300-SXE S200SX, and many others. This one does not fit the S400 housings. Please refer to other listings. Exceptionally high quality 304 Stainless Flange machined from billet and matching USA MADE clamp. Machined from solid billet 304 stainless means its extremely durable and corrosion resistant (no rust!). Welds very nicely to both stainless and mild steel tubing! Has the special "contoured" flare (Borg Warner also calls it 4.21" 3/4 Marmon) to mate to the bevel unique to the only the Borg Warner outlet flange on all these Turbo models. Has the nice 3" ID on the backside of the flange to slip the 3" (76mm) OD tube into and weld. If you wish to use this on a 3.5" tube to build a 3.5" downpipe, just grind away the step and its 3.5" ready! Has a beefy dead section for warp free welding. Use this flange and clamp to make a nice true 3" or 3.5" diameter downpipe! Its ALL stainless! Another high quality part made for FABRICATION PROS.