The Lenz Lithium Pack rcB 1200 works with all Lenz socks, vest 1.0's and bandage 1.0's. The Bluetooth enabled controls lets you manage heat output with a slide of the finger on your smart phone or you can manually adjust the levels. Lenz cares about their customers so they designed their batteries to be compatible with every pair of heat socks, heat vests, heat bandages, and heat gloves so that when one battery dies the others are interchangeable. We all know how annoying it is when companies create a special charging port. Thankfully the batteries from Lenz use a USB to charge. This is super helpful for when you cannot find the charger for you can find a replacement charger at most stores. The Batteries can supply up to 14 hours of continuous use and feature a short charge time thanks to the rechargeable lithium batteries. Whatever your passion is let the Lenz rcB 1200' take the edge off of the extreme temperatures so you can safely and comfortable enjoy work or play this season!