Centennial Defense Systems Guide Rod Recoil 18lb Spring for Smith & Wesson SD9 SD40. Manufactured from certified Aerospace specification materials. All springs are heat treated shot peened and stress relieved for maximum durability. Our springs are designed for CDS guide rods but may work with other brands. Specifications for Centennial Defense Systems Guide Rod Recoil Spring for Smith & Wesson SD9 SD40: Manufacturer: Centennial Defense Systems Color: Stainless Steel Fabric/Material: Stainless Steel Gun Make: Smith & Wesson Gun Model: Smith & Wesson SD9 VE Smith & Wesson SD40 VE Package Contents: Centennial Defense Systems Guide Rod Recoil Spring for Smith & Wesson SD9 SD40 What firearm models does the manufacturer say Centennial Defense Systems Guide Rod Recoil Spring for Smith & Wesson SD9 SD40 is compatible with? The manufacturer says that Centennial Defense Systems Guide Rod Recoil Spring for Smith & Wesson SD9 SD40 is compatible with Smith & Wesson SD40 VE Smith & Wesson SD9 VECentennial Defense Systems 14568: Guide Rod Recoil 18lb Spring for Smith & Wesson SD9 SD40