On the recommendation of another user, I bought this pack for my son who is on TPN (a type of nutrition fed via an iv type catheter through a port in your chest directly to your heart). The VIP 2.0 L Pack is perfect! I took the bladder out, hooked in the TPN bag in its place and tucked in the pump. There is enough room for a few essential supplies, the lightweight, streamlined design is perfect for his slight frame yet easily adapts to fit his wheelchair as well. We are ordering a second pack ASAP! I have no cons, but my son requests some cool Star Wars themed packs😉 Oh, and the bladder? Dad liked this pack so much better than his current one, he’s ordering one for himself and now has a backup bladder. Win!