All-time best seller — the most intuitive grip and doubles as a 10,000mAh power bank. Perfect for pockets or hoodie jackets, multifunctional, and Ocoopa’s hottest warmer (both in temperature and popularity). - Heats up in just 3 seconds - Works as a 10,000mAh power bank - 4 heat levels - 4–8 hours of warmth per charge Ocoopa is the only dedicated rechargeable handwarmer brand focused on complementing your lifestyle. With over 4 million users worldwide, we deliver the perfect palm of warmth to everyone.