This is a used rooftop cargo carrier by Axius.  The bag is roughly 28X28x18 inches. It has a rugged water resistant nylon canvas exterior with a nylon liner.  Let me reiterate it is a water resistant bag not water tight. These bags are not designed for water tightness in the zipper area.  Inside the bag looking out there are some tiny pin holes that allow light from some of the stitch work.  There also some pin holes from light usage.