TechNiche Heat Pax Air Activated Mini Hand Warmer is designed to provide heat and protect against cold temperatures. It is a small heat pack that measures 2 x 3.5 in. which is ideal for Heat Pax powered items like gloves and headgears. It delivers more than 8 hours of constant, safe heat to keep your body from freezing. The heating can be paused by resealing in a sealed canister. This product is non-toxic and biodegradable; it does not use batteries, flames or chemicals to activate.