Keep baby firmly supported with the 6 Inch Firm Spring Coil Mattress Waterproof Standard Crib Mattress. Constructed with quality materials and workmanship. This lightweight mattress offers 96 durable, interwoven, heat tempered, steel coils providing supreme comfort and support. A protective polyurethane foam wrap on each side delivers a plush sleeping surface. Features include a hypoallergenic; foam Insulating layer and lock-stitched waterproof binding for lasting durability and a layer of Fire blocker, a blend of fibers that help isolate the impact of a fire and limit its spread.