I purchased this around 6 months ago and ran around 5-6 tanks through it. It has a 50mm cylinder on it that has been ported. This was the first time I've ported anything, just keep that in mind. The muffler has been modded. I can't guarantee the longevity of the saw, it's 100 percent Chinese, but so far it hasn't had any problems. Sold as is. $245+shipping. Bar and chain not included. I maybe interested in trading for a nice Husqvarna 350.