Our guide rod is precision CNC machined from the highest quality stainless steel and heat treated for a lifetime of usage. Includes a solid stainless steel cap with Black Nitride finish. The double hole design allows quick and easy spring changes, or have multiple assemblies with alternative spring weights ready to drop in for use with suppressor or different loads. Compatible with 1.0 & 2.0 with 4.25″ or 5″ barrel, and M&P®9 M2.0™ Metal. (2) 1/16″ wrenches are included.