4 inch Size Memory Foam Crib Mattress & Toddler Bed Mattress, Fits Standard Full Size (52"x 28"), White - Walmart.com
Amazon.com : My First Memory Foam Crib Mattress, Breathable Crib Mattress with Removable and Waterproof Cover, Hypoallergenic, Standard Size, 51.63" L x 5" H x 27.25" W : Memory Foam Toddler Mattress :