When our backs have been battered by miles of backpacking and long nights sitting on stacked rocks, logs, and camp chairs, the Ignik Outdoors Backside XL Heated Pad Cover provides portable heat for any seat. The cover fits over a camp chair (and other chairs) to warm our back and also can lay flat to warm two people at once--not only to heat us up but also to loosen us up, so we can keep on hiking and camping. The Backside Heated Pad Cover requires a minimum of 12v and 2. 0 amps, and it works with USB-C Power Delivery power banks and other 12V power supplies (battery not included) to heat our backside at the campground, dock, or backyard barbeque.