The Walker Exhaust 21337 Quiet-Flow SS Exhaust Muffler is engineered to provide superior performance and durability for commercial vehicles. Constructed with 100% stainless steel, this muffler offers enhanced corrosion resistance, extending its service life compared to traditional aluminized mufflers. The internal drainage system effectively reduces moisture accumulation, mitigating the risk of rust and prolonging the component's longevity. Designed for easy installation, the muffler features OE-style hangers, brackets, and pipe routings, eliminating the need for specialized fabrication or welding. Its robust construction includes internal partitions and mechanically joined tubes that accommodate thermal expansion and contraction, minimizing distortion and ensuring structural integrity under varying temperature conditions. The spun-locked heads and OE-style spot welds further enhance stability and durability. Acoustic performance is optimized through OE-style louvered tubes that lower noise levels, while domed heads help reduce radiated noise, delivering a premium factory-style sound quality. The muffler's design has been validated through acoustic and flow testing, ensuring reliable performance and compliance with industry standards. With dimensions of 21.5" in overall length, 18" in body length, 9.75" in body width, and 4.25" in body height, the Walker Exhaust 21337 Quiet-Flow SS Exhaust Muffler is a direct-fit replacement that meets or exceeds OE specifications, making it a dependable choice for fleet operators seeking to maintain optimal vehicle performance and minimize maintenance costs.