Ace 1 Arms G17 Tactical Outer Barrel Set for the Tokyo Marui model 17, simply drop in and you are ready to go. The great thing about this is that there is a 14mm CCW thread allowing you to add a suppressor if you want.
The outer barrel and slide is made out of high quality alumium. It also comes with a 120mm precision inner barrel. You are replacing a plastic slide with a metal slide allowing for a more snappy recoil action while sticking to the Marui accuracy which we all know and love.