The 3.7v Powersheer Wireless Heated Sock Batteries are premium power banks for your Mobile Warming Merino 2.0 Wireless Heated Socks designed to provide longer heat times between charges with its 4000mAh capacity, and it has USB-C quick charge input for faster recharge times.  Whether you’re hitting the slopes, trekking through the snow-covered landscapes, or simply bracing the winter chill. Embrace the winter season with the assurance that your feet will stay warmer longer, thanks to the advanced features of these exceptional batteries.