Exclusive Tri-Size DC Ports No Adapters NeededThe only heated vest battery pack with three built-in 7.4 V DC jacks (3.5 mm, 3.8 mm, 4.0 mm). No dangling adapter cables, no extra bulkjust plug and play. Compatible with most 7.4 V heated jackets and vests Heat Your Gear + Charge Devices at OncePower your 7.4 V heated apparel while charging your phone or tablet via USB-A and USB-C at the same time. Stay warm and connected all day without unplugging. (Note: not for powering two DC garments simultaneously.)