Built in heat therapy pad can warm up your joints and promote blood circulation. Built in cooling therapy relieves pain in shoulders and knees. Perfect for heeling; dislocated AC joint, sprains, tendonitis, paralysis, stiffness, and soreness. Also helps relax shoulder muscles and speed up heeling time. Two powerful motors provide strong vibration with 3 different speed levels to relive shoulder pain. Perfect for use at home or on the road. Ice bag included. Powered by USB plug.