Thick polyester material which is slick and shiny outside, and very soft on the inside for a very nice wear. This material was called "elastic" in the past, it is virtually undestructable - will last forever! It does not form any cotton balls, and washes very nicely.You will love the quality and the look of this track suit! I have sizes M, XL.. There are more sizes and more models on the above link. The item "Classical Adidas tracking suit vintage old school tracksuit LIGHT BLUE M, XL" is in sale since Monday, February 15, 2021. This item is in the category "Clothing, Shoes & Accessories\Men\Men's Clothing\Activewear\Tracksuits & Sets". The seller is "uk-rr2010" and is located in Bruxelles. This item can be shipped worldwide.