ABIL Premium Blue Bag Pack Pattern 4

A backpackalso called knapsack, schoolbag, rucksack, rucksac, pack, sackpack, booksack, bookbag or backsackis, in its simplest frameless form, a fabric sack carried on one's back and secured with two straps that go over the shoulders, but it can have an external frame, internal frame, and there are bodypacks.