Build Quality MagnaFlow Performance mufflers are 100% stainless steel (Polished or Satin Finish) and lap-joint welded for solid construction and rugged reliability even in the most extreme conditions. They feature a free-flowing, straight-through perforated stainless steel core, stainless mesh wrap and acoustical rock wool to deliver that smooth, deep tone. Mufflers are packed and stuffed tight with the sound suppression material...it's what makes straight pipe performance sound so smooth. Prime quality materials, chosen specifically with looks, performance, and longevity in mind, ensure long life and, virtually no sound degradation over time. Magnaflow Exhaust Systems and Magnaflow Mufflers are backed by a Lifetime Warranty. The graphic illustration below below has outlined the primary performance/durability features built into each Magnaflow muffler, click on a point of interest for a more in depth look into the heart of wide open performance.