Hooker 4 inch Universal Sidemounts reduce backpressure, improving low end torque for better performance and fuel economy. The classic Hooker 4 into 1 (NOTE: 3 tubes are dummies) collectors utilize huge 21⁄8" diameter primaries mandrel bent to maintain a consistent inside diameter for maximum flow. Our 4" 16 gauge sidepipes utilize long lasting slip-in mufflers. These mufflers are easily removed for racing purposes and are available in a performance style (glasspack) or quieter reverse flow style (all metal). Show quality chrome finish.