This jacket is pretty awesome.  I've been looking for one of these that would fit me for ages, and the GR19 that this seller had in stock is the biggest  I've found, so I took a chance.  I'm 6'6" tall, 270 lbs with an athletic build.  I usually take a 3XL tall in shirts and jackets, and the GR19 is close to that.  As with a lot of European sizing, they seem to run a little small, kind of an athletic or trim fit, and  this garment is no different.  I can wear it just fine, as long as I don't wear anything too bulky under it. It's a little tight in the shoulders and chest, but I must mention that I'm larger than your average human in those area's due to years and years in the weight room.  So, it might fit an average Joe just fine, but if you're built like a linebacker, try to find the next size or two up, if possible.  The length is fantastic for a guy my height. The bottom of the jacket hits me at mid thigh, which is great. The sleeve length is adequate as well, but I find that they fit better if you leave the velcro un-done. The weight of the material and the workmanship are good, and I really like this jacket a lot, but will continue the hunt for a GR20 for layering.