A bag that has been around for a long time. It was used even in the late 40's from military personel, sailors, marines and later on even from surfers. Now for some years it also became a very stylish fashion piece that most fashionistas have in their wardrobe.
A grey & black duffle bag that you can also buy online on ASOS and its by French Connection The Lillia Duffle Bag.
Another duffle bag in a black color that you can also find online on ASOS and it's listed as Patchwork Duffle Shoulder Bag.
My personal favorite The Moschino Red Duffle Bag.