The Walker Exhaust 21563 is a high-quality exhaust muffler designed to provide superior performance and durability for a range of vehicles. Constructed entirely from corrosion-resistant stainless steel, this muffler offers a longer service life compared to traditional aluminized mufflers. Its internal drainage system effectively reduces moisture accumulation, preventing rust and extending the muffler's lifespan. The muffler features a direct-fit, bolt-on design with OE-style hangers, brackets, and pipe routings, ensuring easy installation without the need for specialized fabrication or welding. Internally, the muffler is equipped with OE-style louvered tubes that lower noise levels, while OE-style domed heads help reduce radiated noise, delivering a premium factory-style sound quality. The internal partitions and mechanically joined tubes allow for expansion and contraction during temperature changes, minimizing distortion and enhancing structural stability. Spun-locked heads and OE-style spot welds further contribute to the muffler's durability and longevity. Acoustic and flow testing have validated the muffler's design, ensuring consistent performance and quality OE-style sound. The Walker Exhaust 21563 is compatible with various Ford and Mercury models, including the 2006-2010 Ford Explorer, 2006-2010 Ford Explorer Sport Trac, and the 2006-2010 Mercury Mountaineer. This compatibility makes it a reliable choice for fleet operators seeking a durable and efficient exhaust solution.