Mountain Hardwear Unisex Grotto 35 L Roll Top BackpackMountain Hardwear Unisex Grotto 35 L Roll Top Backpack The Mountain Hardwear Grotto 35L+ Backpack is designed as a do it all day pack, and it lives up to the bill. We have trusted this pack on sport route sessions, work commutes, and short hikes. The combination of style and function is really where this backpack thrives. Material: 100% polyester Fabric type: Nylon Cordura, Dimension Polyant X Pac Back Panel: Foam Capacity: 35 L Features: Water