【Double-Sided ＆ 4-Level Heating】Fast heating double sides in seconds, long-lasting heating supply up to 4-8 hours, provide constant warmth for you, won't hurt your skin. 4 levels of temperatures (95-100℉/100-107℉/107-118℉/118-131℉) for you choose as you need.Press the switch and instantly release the warmth for you.【Large Capacity】5200mAh Rechargeable hand warmer with USB-C charging port ensures a long using time. Also can as a spare power bank give a full charge to most digital devices. Compatible with iPad iPhone Samsung and more smart phones. Tri-level indicator to remind you of the remaining charge and heating status.【Superior Safety】Certificated by CE, FCC, ROHS, PSE, METI, UL. Made of high quality Aluminum and flame retardant ABS material, eco-friendly lithium battery. Its built-in intelligent protection system provides effective protection. Shockproof, Anti-scald, Anti-skid, Explosion-proof. Completely safe heat transfer.