XFORCE - 3.5" Inch Round Metallic Hi-Flow Racing Catalytic Converter (100 Cell). The XFORCE Metallic Hi-Flow Racing Catalytic Converter (100 Cell) is a 3.5" round component designed for optimal performance. Its inlet measures 3.5 inches, with a diameter of 4.5 inches and a length of 6 inches. This round catalytic converter is made from high-quality metallic materials, making it a top choice for racing enthusiasts. Maximize your racing performance with the XFORCE Metallic Hi-Flow Racing Catalytic Converter (100 Cell). Its 3.5" round design is specifically crafted for optimal efficiency, with an inlet diameter of 3.5 inches, a diameter of 4.5 inches, and a length of 6 inches. Made from high-quality metallic materials, this catalytic converter is the perfect choice for serious racers looking to take their vehicle to the next level.