4 Pack Holiday Reusable Handwarmers Color: Red Material: Plastic Condition: New - Open Box for Photos INSTANT HEAT WITH NO ELECTRICITY: Snapping the flex disc starts to generate instant heat, reaching up to 55 degrees. The internal chemical reaction generates long-lasting heat (approximate duration of heat is 40-60 minutes). Put it in your coat pocket and kept kneading it with hands in the pocket so the heat is retained. When it loses its warmth, simply drop them into boiling water about 5 minutes to reset them (the crystals completely liquefy). Remove and allow to cool to room temperature. They are then ready for use again and again. SAFE, NATURAL HEAT: Ingredients: Durable PVC pouch, 12% distilled water, 88% sodium acetate, metal disc- A great, fun way to keep your fingers warm this winter. They work great in pockets but just don't sit on them. Keep your hands warm during all your outdoor activities when it is cold outside.