It's a MS390 with a 20 inch bar, a little pricey, but I have never regretted buying it two years ago. I've used it from cutting everything from small brush (gets heavy) to 20+ inch cherry and poplar.
Nice tractor, I have to agree the oranges work well..... I have a CK20HST and well the exact same saw except I have a 28 inch bar and I love them both.... I wish at times I had more power on the CK but that is just to get the job done quicker seat time isn't going to be a issue at my place. Even with a large machine I will have way more seat time than I have time to spend using it up.