Open Battery Compatibility

The Polar Seal zip tops are powered by an external 5V compact USB power bank of 2A or more (with USB-A connector) (not provided) delivering 5,000 to 10,000 mAh, which you can procure online or from most electronics stores in your country.

This open compatibility allows you to choose the power bank of your liking, in terms of brand name, size, capacity, color etc.

You insert this power bank in the left pocket and connect it to the USB plug located inside the pocket. You can use the right pocket to carry your phone, wallet, or an extra power bank for longer heating time.