This is the newer version that has an internal stinger. Will fit Stihl MS660, 066 and Chinese copy saws (OEM or aftermarket) with this setup the manifold bolts directly to the cylinder.
This is meant for competition and closed course racing only. Here are a few videos if you would like to learn more or see the pipe in action. And one to show HP gains. This particular pipe will only work on saws without a wrap handle. Feel free to ask questions.