The first time they see or try Core's Pressure Point Therapy Packs, many people say something like, "That's ingenious!" when referring to their design, which targets relief from headaches, low-back pain and muscle soreness by combining pressure point and cold therapies. Linked therapy balls are encased in non-toxic cold therapy gel and ergonomically positioned to fit pressure points at the base of the skull or lower back. Your own body, the back of a chair, a mattress, or whatever is suitable for the situation, provides the pressure. The DualComfort cover offers two "frost-free" treatment surfaces - one for slow-release, the other for rapid-release, so you also control the delivery of the medically accepted cold therapy. The balls stay soft and pliable when stored in freezer. Both sizes bring helpful relief to virtually any spot on the neck or back.