The Sealy Celestial Cool Antibacterial 2-Stage Hybrid Infant & Toddler Crib Mattress combines innovative copper cooling gel and firm posture support coils. Copper foam uses natural copper elements that helps create a cooler foam compared to regular memory foam toppers. Laboratory tests showed our copper foam showed a reduction in product-damaging bacteria after an hour of contact. 204 American-made springs are tested for lasting durability and resiliency. Secure steel edges support babies throughout the surface. A lab-tested, EPA-approved Staph-Gard antibacterial cover helps eliminate harmful bacteria on baby's mattress. The cover is 100% waterproof, stain-resistant and wipe clean. Lock-stitched waterproof binding and an airflow pocket is designed to help keep the mattress fresh. Sealy crib mattresses are GREENGUARD GOLD Air Quality Certified for a healthier indoor environment. Fits snugly inside all US standard-size cribs and toddler beds. Passes ASTM crib mattress standards for non-toxic for babies made without phthalates, lead and passes ASTM standards. Measured to fit all US standard full-size cribs and toddler beds. Premium support, comfort and lasting durability. More babies sleep on a Sealy than any other brand.