New to the market, the Dream on Me 3" Spring Coil Portable Crib Mattress is the first of its kind. You no longer need to compromise comfort for support. The interwoven steel coils are wrapped in a hypo-allergenic, polyurethane foam and protected with a waterproof cover with Lock Stitch venting. Rest easy knowing this mattress is constructed with quality materials and workmanship in the USA. The waterproof, hypo-allergenic, antibacterial, cover aids in the prevention of mold, mildew and odor and easily wipes clean with warm water and a mild soap. This fits Standard 24 x 38 portable cribs and play pen. Lead and phthalate free this mattress passes the Federal Standard Flammability Standard 16 CFR 1633.