Is your child ready for an upgrade to a big-kid bed? It's time to transform your Sleepi Crib to the Sleepi Junior Bed (conversion kit sold separately). The Sleepi Junior Mattress by Colgate is specially made for your child's bigger bed. It's made of high-quality hypo-allergenic foam, blending excellent support and comfort. The underside of the mattress cover features a waterproof backing, while the top is made of durable, non-toxic Damask cloth.