X-Pipe design synchronizes the balance of the exhaust pulses from each bank of cylinders based on firing order which increases velocity and scavenging from each cylinder. JEGS X-Pipes are designed for cars and 2WD trucks with long tube headers. Will not fit 4x4's. Manufactured from fully aluminized 16-gauge 2-1/2" diameter mandrel bent tubing. Includes four 40° elbows, an X-tube center section and eight clamps. Requires the use of I.D. style reducers 555-30031 to 555-30037 (sold separately). For off-road use only! Made In USA.