You close this duffle bag with a zipper. It only comes in one colour, green, but it does look quite neat and it holds 39 litres.
From Adidas
4ATHLTS Medium Duffel Bag - Olive Strata / Black / White - 1 Size
JD Sports
adidas 4ATHLTS Medium Duffel Bag - Olive Strata - Olive Strata / Black / White - 1 Size