Features A Plush Multi-ply Cover Designed To Focus Heat Toward The Body Andprovide A Snug Secure Fit This ?unplugged? Version Of Moist Heat Therapy Offers The Maximum Inportability And Convenience The Patented Non-allergenic Crystal Fill Does Not Leak Smell Or Encourage The Growth Of Fungus And The Porous Surface Traps Up To 40% Of It's Weight In Atmospheric Moisture For Reliable Moist Heat Therapy Natural Moist Heat Works In Three Ways: - Blocks Pain Signals To Your Brain - Relaxes Muscle Tissue To Relieve Cramps Or Spasms - Increase Circulation To Enhance The Healing Power Of Your Own Body Outer Multi-ply Fabric Includes A Vapor Barrier To Direct Maximum Moist Heat Where You Need It Most Wide Elastic And Velcro Strap Holds The Heat Therapy Snug And Secure Against Your Skin With Gentle Compression Holds Pack In Place While You Continue Regular Activities More Economical Than Disposable Single-use Heat Packs