The Nike Pro Long Sleeve Revolution top is a light baselayer with superior compression technology.Dri-Fit - This high-performance, microfibre, polyester fabric wicks sweat away from the body and moves it to the fabric surface, where it evaporates. As a result, Dri-FIT fabric helps you stay dry and comfortable.Flat stitched seems - To help reduce chaffing on the neck and shoulders and also gives greater comfortFabrics - 74% Polyester - 14% Nylon - 12% Elasten/SpandexTIGHT fit - For a very figure-hugging, close-fitting style. A fit that moulds to the body for sustained physical concentration