• Instant activation: flexible disc to activate heat instantly. • Temperature up to 55°C, heat duration 40-60 minutes. • Reusable: reactivate by boiling in water for 5 minutes. • Ingredients: PVC bag, distilled water, sodium acetate, metal disc. • Caution: do not heat in microwave, avoid contact with sharp objects. • Instructions for use: click on the disc to activate, gently knead to feel the heat. • Recharge: boil in water for 5 minutes to restore. • Retains heat for 30-40 minutes. • Do not leave in contact with the bottom of the pan while boiling.