I purchased one of these for myself four years ago, I still use it on every bike ride I take. The rides are plentiful, including commuting, pleasure crafting, and a few tours; it has held up very well to all of this use. I am 5'10" and 190 lbs., I wear the large, it fits snug but not tight and I can wear it over just a t-shirt all the way up to a fleece backed too-big-for-me softshell jacket. I have bought two more since to give as gifts, the recipients have been pleased as well. An added wonder is the extra room many motorists give a wearer of this vest as I have ridden just a handful of times without this since it's purchase, people give people without this vest less room on the road, it is a fact. A wonderful product, safety first is a good policy.