Guide Rod
I think STI calls it the Recoil Master. What it is is a double spring set up that replases the regular guide rod, and bushing. I think you can use it in any 1911. As per STI the light is for the 9mm and they have a heavy for the 45. For the most part it is just a drop in replacement, although we did have some issues getting it working right at first. Once the gun got a few rounds thru it and started to smooth out it started working fine. There is also another manufacture that makes one also, I think it is springco, both are listed in Brownells.
