Nook presents the world's most considered infant mattress, made lighter. The Nook Pebble Mattress Lite features new dual air layers fostering oxygen flow inside the mattress. The certified non-toxic foam core provides support while the superior softness of all-natural eucalyptus provides comfort. The Nook Pebble Lite Mattress is highlighted by a two-sided design ensuring a firm and breathable sleep space for infants. Flip the Pebble Lite over for a plush yet equally breathable toddler mattress. 28" x 53" x 4."