Centennial Defense Systems MOD4 Stainless Steel Guide Rod Assembly for Smith & Wesson M&P 5in Barrel Stainless Steel No Coating Button Head Allen. This eliminates guide rod flex and ensures it will not chip crack or break like plastic guide rods providing a lifetime of reliable service. Flat wound recoil springs are manufactured of certified aerospace spec materials heat treated shot peened and stress relieved to maximize durability. The screw tip is easily removed to allow the user to change spring weights and fine tune the recoil spring to the ammunition of choice. Like all Centennial Defense Systems products our guide rods are designed manufactured finished and assembled in the USA. Finishes Available: Black Blue Burnt Bronze Glock Gray Glock Tan Hi-Viz Orange Nickel OD Green Pink Purple Red Satin Aluminum TiN (Gold) White Zombie Green Fits S&W Full Size M&P Models with 5 Barrels for 9mm .40S&W .357SIG Guide Rod Versions: MOD1 = Allen Screw MOD2 = Flat Face Screw MOD3 = Torx Screw MOD4 = Button Head Allen Screw MOD5 = Flat Face Button Head Screw Factory Recoil Spring Weight S&W Models M&P Factory Spring Weight is 16lbs Alternate Spring Weight 11 15 LB Recoil Springs Are for Reduced Power Loads 17 - 24 LB Recoil Springs Are for Heavy Ammunition Loads +p and +p+ Note: Only the screw will have the selected finish with the exception of Black and TiN (Gold) which can be applied to the rod as well. Specifications for Centennial Defense Systems MOD4 Stainless Steel Guide Rod Assembly for Smith & Wesson M&P 5in Barrel w/Button Head Allen Screw: Manufacturer: Centennial Defense Systems Fabric/Material: Stainless Steel Gun Make: Smith & Wesson Gun Model: Smith & Wesson M&P 5in Package Contents: Centennial Defense Systems MOD4 Stainless Steel Guide Rod Assembly for Smith & Wesson M&P 5in Barrel w/Button Head Allen Screw What firearm models does the manufacturer say Centennial Defense Systems MOD4 Stainless Steel Guide Rod Assembly for Smith & Wesson M&P 5in Barrel w/Button Head Allen Screw is compatible with? The manufacturer suggests that Centennial Defense Systems MOD4 Stainless Steel Guide Rod Assembly for Smith & Wesson M&P 5in Barrel w/Button Head Allen Screw is compatible with Smith & Wesson M&P 5inCentennial Defense Systems 12721: MOD4 Stainless Steel Guide Rod Assembly for Smith & Wesson M&P 5in Barrel Stainless Steel No Coating Button Head Allen Screw 15lb Spring