These are Vinyl yet with a 'safe' poly fill, whatever that exactly means. If you are in the toss away every non organic item crowd, the fill is different, yet not labeled no VOC or low. Anyhow, the vinyl is durable and quality, it's not cheap, and is what makes these more durable than leather, which we have elsewhere, along with the unique & supportive filler. These cubes can be opened up via a 'hidden zipper' which I cannot find, if ever needed. They are well made, double stitched, clean easy, can use anywhere and meant for kids (small cubes). Big bonus is you can easily transport these supportive, cushy kid cubes anywhere. Even take em to a vacation spot, keep the seats stored for grandkids, or your kids, use at an outdoor event, or in a tent, just enjoy. You may even want to buy 2. Also can use as a foot/leg rest.