LONG-LASTING HEAT: Air-activated, unscented, and ready to use. Heat duration lasts up to 10 hours. Max temperature: 160°F (71°C); Average temperature: 136°F (58°C). OPEN AND GO: Simply open package and shake. Reaches max temperature in 15-30 minutes. No batteries, no charging, works anywhere. If the temperature begins to decrease, expose warmer to air and shake. OUTDOOR: Perfect for skiing, snowboarding, hunting, construction work, outdoor sports, and winter commuting. Stays warm from morning to evening. SAFE & NATURAL: Made with iron powder, water, vermiculite, activated charcoal, salt, and high water absorption resin. TSA-approved for flights. Odorless, non-toxic, eco-friendly disposal. WARMER SIZE: 3.7" x 2.7" x 0.1"; BOX SIZE: 8.5"L x 5.5"W x 6.5"H.