This is a stainless steel guide rod for a Ruger SR 40 pistol Handgun out of 304 stainless steel. The rod is made of only the finest stainless steel material to replace the plastic factory rod in your Ruger SR-40. Our rods are measured to factory specification and we ensure the finest fit and finish on all of our parts. These parts are now available for your Ruger SR40 firearm. Be confident in your firearm and add a stainless steel guide rod for your Ruger today. This is a drop in unit that comes with a spring as well.