true, Synthetic Fiber, Memory Foam

Sersper Memory Foam Baby Crib Mattress and Toddler Mattress, CertiPUR-US - 52"*27.5"*6"

6 inch Crib Mattress, Baby Crib Mattress and Toddler Mattress, Breathable Waterproof and MovableCover - 52"*27.5"*6"

Beautyrest® Black Diamond 2 Stage Crib and Toddler Mattress - 27.5 x 52 x 6

Crib Mattress with Washable Cover,Dual Sided Baby Crib Mattress &Infant Toddler Mattress, Water Proof Mattress

52"*27.5"*6" Crib Mattress,Washable Waterproof Cover for Baby and Toddler,Fit for Standard Cribs and Toller Beds