Amazon.com : GRT 2 Pack Waterproof Crib Mattress Protector, Quilted Baby Mattress Cover Fitted Deep Pocket from 4" up to 9", Extra Soft Breathable & Noiseless Toddler Mattress Pad 52"x28", White :
Sealy Waterproof Crib and Toddler Mattress Pad - 2 ct, Hypoallergenic - Walmart.com