Think ziplock with a flapper valve.
Worth about 40 cents.  Returned it immediately.  You have to rolled the bag up tightly with your clothes in it to squeeze out the air.  Kinda like deflating an air mattress.  Harbor Freight has 3 packs with actually vacuum ports for about $6.  Cheap, overseas quality, but definitely thicker plastic, better sealing, and better use experience that this product.
Rating: 1 stars