The Pro-Tec Acuback is the only heat-able self care too on the market. This device is intended to relieve stress and pain in muscles and joints. Not only can it be used to correct posture it works well on the back neck shoulders legs and feet. To correct posture place behind back when sitting or driving. The Acuback features a Spine Alignment Belt around the center of the tool that loosens muscles and joints directly at the spine. The Acuback is easy to use.Color: BlueFeatures:-Water filled.-Latex free and hypoallergenic.-Microwaveable; Heat for 90 seconds in the microwave or boil for 12 minutes.