I assume that this is mostly used by folks who are thinking about buying their first rope. Despite the fact that there can be as many as a dozen ropes or more in your local shop most of them will not apply to your needs. So here is a slight break down for your first rope.If you are a mountaineer then weight is always a issue. No I am not saying your a fat pig and should be watching how many calories you consume. I am talking about the weight of the rope. For most glacier travel situations I will get the skinniest rope that I can. In fact I will often use a half rope for ski touring or something like that peak you see in the background at the opening of this vid. The other important thing is dry coating. This prevents water from getting absorbed by the nylon. Old frayed ropes can take on 10 pounds of water in a worse case scenario. ;Rock climbers can save their money as it is of no value out on the crags and cliffs. As your first rope don’t go buying anything to thin. Your looking for a rope in the 10.2 to 10.5 mm range. By the time you wear this rope out you are going to have a pretty good idea what you need as your next rope.