baby exercise mat

https://bedpillow.bloggersdelight.dk/2024/08/04/the-best-advice-you-could-ever-get-about-fisher-price-piano-play-mat-for-baby/

You should inspect your mat frequently for indications of wear and tear like threads being loose or damaged foam. Repair or replace as required. Be sure to keep it in an area with no moisture to limit mold growth.