The Kari Traa Kari 30L Bag is a medium-size duffel bag for carry-on traveling and hitting the gym. Made from durable, water-resistant PVC material with polyester, it has multiple handles and unique, padded shoulder straps so you can carry it backpack-style. The heavy-duty zips can take being slung around and there is a secure mesh pocket to stash things inside. One size.