Nancy Zeiman had a show on these, but I can only find her activity mats now. However, at the seams there were round tabs, prairie tabs, little pockets, etc. Honestly, I am cringing at the idea of a zipper after seeing someone zip a finger into one. It wasn't pretty. And depending on the depth of dementia, I'd be cautious about the ones with beads on string. Like children, these can pose a choking hazard if some poor soul decides to eat them.