The official LASundays backpack has plenty of room with a big inner pocket, a separate section for a 15'' laptop, a front pocket, and a hidden, "stash spot" pocket at the back.
Made from 100% polyester
Dimensions: H 16⅞" (42cm), W 12¼" (31cm), D 3⅞" (10cm)
Silky lining, piped inside hems, and a soft mesh back
Padded ergonomic bag straps from polyester with plastic strap regulators