Conforming Hypo-Allergenic Soy based foam core, a firm layer and a softer layer that can be interchanged, not inexpensive innersprings. No chemical adhesives. Waterproof cover wipes clean easily and feature seamless tops. There is no stitching on the top surface edges where moisture and bacteria can enter the mattress. Bottom zippered cover allows you to be sure even the inside of the mattress is clean and sanitary. 27.5x52x5.5" Made in USA. Young children are the most vulnerable to toxic exposures. Government mandated flame retardant chemical based fire barrier is zippered and removable. This allows access to inner components to flip, check for mold or mildew, and make sure even the inside is clean and sanitary.