The material is thick and strong. My male cat is almost 13 pounds and there's no give. This is very sturdy, it was super easy to zip together which was a concern while viewing other brands. The zipper seems sturdy and well made. It came with 3 fuzzy balls which my cats are playing with. My cats like playing on, inside and around the bed. It's the first cave type bed that they both like and play in. It does not have the peek-a-boo holes in it like others I looked at but that doesn't seem to effect them playing. They just hang over the opening and paw at each other. Overall, I would recommend this cave for cats enrichment, play and sleeping.