Get Better Sleep: Serta Density Pillow The Serta Density Pillow is the perfect accompaniment to a quality mattress. No matter how luxurious your mattress is, it won't compensate for a floppy, flat and uncomfortable pillow. This high-density pillow is made to stay soft, supple but very supportive. Whether you sleep on your back, tummy or side, this pillow cradles your shoulders, neck and head to help ensure a comfortable long-lasting sleep.  It offers great support to help eliminate waking up with neck or back soreness. Made from 100% hypoallergenic materials, this pillow is the perfect solution for people with allergies or sensitivities to natural pillow products.