Come and see our amazing products. Made of high-tech aircraft-grade aluminum and ABS matrial, eco-friendly polymer battery. Shockproof, Anti-scald, Anti-skid, Explosion-proof. The optimized and upgraded circuit completely eliminate all kinds of poor contacts to ensure the lifetime of Four Heart reusable hand warmer and provide protection against over discharging, over charging, overheat, and short circuit. Warm your hands in 1-3 seconds. Press the switch and instantly release the warmth for you. 4" L x 2.4" W The price includes the shipping cost to ca, QTY over 10000pcs by ocean. Pls confirm further with us if any query about packing info, inventory status and time schedule.