The Footprint Copper Spur HV UL 1 from Big Agnes is specific to the Copper HV UL 1 tent. It attaches to the bottom of the tent and is integrated with the rainfly. This footprint has several uses: it provides extra protection under the tent's floor to enhance its waterproofing and longevity, and it also allows the tent to be used in "tarp" mode, meaning only the rainfly and the footprint are set up. In this case, the shelter is highly protective while being ultra-lightweight!