The Elastogel Hot/Cold Shoulder Sleeve is perfect for the hard to treat contoured areas of the shoulder, upper and lower arm, upper chest and upper back areas. Used to offer hot or cold therapy to either the left or right shoulder. The tough, flexible gel will not leak if punctured and the 4-way stretch material will help ensure product durability and effective therapy and pain management. Like the other Elasto-Gel products, this can be put in the microwave for heating or in the freezer for cooling. Stays soft and pliable, even at -20 F. Provides 20-40 minutes of treatment per application. Available in 2 sizes. Normally for home use. Used in medical clinics worldwide to treat muscle and joint pain, hot or cold therapy will last 20-40 minutes per application Comfortable Lycra cover conforms to your body Will not leak if punctured. The Elastogel Hot/Cold Shoulder Sleeve is made utilizing a tough, flexible high glycerine gel that is covered with a four-way stretch material that allows maximum conformity, hot and cold transfer and comfort. It is designed to help provide either hot/cold therapy for minor muscular and soft tissue injuries to the shoulder area. Sizes: Small/Medium designed for biceps up to 11 inches. Large/XLarge designed for biceps larger than 12 inches.