Our special foam is naturally mold resistant. No anti-mold chemicals are added to the foam, and the effect will not wear out over time. So no bad smell after a few days, even when not stored in a fridge. Long lasting, you just need to rinse it from time to time with fresh water. For the Painter v1 (orange lid), Painter Lite (orange strap) and Painter Lite Blue (blue strap) only.