Tropicfeel Nest Backpack, navy, in excellent used condition. Expands from 16L to 30L. Has a lot of pockets and organization. Hidden pocket on back for small items, stowable kangaroo pocket on bottom, luggage pass through strap, collapseable water resistant pouch in main compartment, fleece lined top pouch, water bottle pocket, mesh system on front for more storage, padded laptop compartment. See pictures.