These high quality round catalytic converters are designed to work for a wide variety of universal applications. Features include a compact 4.00-inch diameter x 8.00-inch long spun outer casing for ease of fitment in tight spaces along with High Flow 200 Cell Metallic Substrate for severe-duty/high temperature applications. They feature a 2.50-inch inlet/outlet diameter connections and are intended for customized Pre-OBDII racing applications, and as a "green" solution for vintage hot rods or vehicles that did not originally come equipped with catalytic converters from the factory. These are Not intended to meet on-highway compliance programs and are Not Legal for Sale or for Use in California. Also, may Not be Legal in States that follow CARB regulations.