Exterior features a side pocket with a cinch (can hold a water bottle) and a loop for keys, etc. Interior features a key leash and a zip pocket. Unzip strap and re-attach ends to rings for use as a traditional backpack, or leave strap zipped and attach strap through either ring for use as a sling. Zip closure. Capacity 6 L.;9.00" w x 16.00" h x 3.50" d