Rival Arms Guide Rod Assembly for S&W M&P9 4.25 is crafted from durable stainless steel replacing fragile plastic guide rods for improved reliability and performance. The black-finished stainless steel construction resists wear and eliminates flex for enhanced accuracy and consistent functionality. Designed for a perfect fit it ensures feeding and ejection reliability while standing up to rigorous use. Built for precision and a lifetime of dependable service it's a must-have firearm upgrade.