The 2-Stage Waterproof Rectangular Mattress introduce a breathe flow technology. Their mattress is designed to fit standard full size cribs it features a 80 durable, interwoven, heat tempered, steel coils providing supreme comfort ,hypo-allergenic, certipur-us certified layer for comfort these mattress are covered with a breathe –flow material on the infant side and a waterproof cover on the toddler side with lock stitch seams. 2-In-1 Twilight Breathable 5" Crib and Toddler Mattress the federal flammability standard ,rest easy knowing this mattress is tested for phthalate and lead and constructed with quality materials.