1. Improved heating speed Eliminate the need for pouring water and reduce the risk of burns with constant temperature control. Our graphene hand warmer ensures instant warmth in just a few seconds thanks to its lightweight design 2. USB charging solution Eliminate the limitations of fixed power supply with this graphene hand warmer, which can also be connected to a mobile power supply. Equipped with a USB interface, it lets you travel with ease and provides warmth anytime, anywhere 3. Comfortable and softThanks to its stateoftheart heating technology and longlasting performance, this graphene hand warmer is designed to provide you with quick warmth in cool temperatures 4. Effortless heat control With 3 adjustable modes and intelligent temperature regulation, the graphene hand warmer adopts a doublesided heating method to ensure worry warmth without burns at high temperatures