This canvas duffle bag is well constructed out of tough, heavy duty material.  It closes on top, not with a zipper but with a metal loop.  The loop is on one side and grommets on the three other sides.  Put the metal loop through the grommets by folding down the sides and secure by using the hook on the strap.  I've never used such a closure, but it's effective.

This is a well made bag.  I imagine it can take a beating.  Great for camping.  I bought it for a tent, but the tent is huge and just a tad too big for this bag.  I was able to squeeze it in, though.  It works.