- XFORCE - 2.5" Inch Inlet Single Tip Oval Varex Muffler. Barrel Shape: Oval. Type: Double Walled Straight Cut Tip / Flanged. Material Type: Stainless Steel. This expertly designed XFORCE muffler features a 2.5" inlet, single tip for maximum flow and performance. Made with double-walled, straight cut tip and flanged construction, this muffler is built to last. Crafted from high-quality stainless steel, it offers both durability and superior sound control.