The Onyx Cool Shoulder features a plant-based phase change material that cools to a skin-safe and soothing 58 degrees. This wearable therapy includes three straps to conform to the shoulder plus six additional areas: neck and upper back; lower back/lumbar; hip; knee; foot or ankle; and forms into a cooling cap for migraines, headaches and hair loss. This cool (not too cold) device is safe to wear directly on the skin without risk of ice burn, frost bite or vasoconstriction. Cooling PCM safely permeates tissues to relieve pain and draw heat and inflammation away. Maintains constant 58 degrees cooling for about an hour, depending on use. Re-cools in the refrigerator in 30 minutes. Latex-free and made in the USA! To clean, wash with mild soap and water then air dry.