You don't need it for waterproofness, NEMO floors have that covered, but if you will be spending a lot of nights on gravel, this could add longevity to your tent. Prolong the life of your investment with a Footprint!Specs:Hornet 2P - Weight: 6.9 ozLosi LS 2P - Weight: 9 ozLosi LS 3P - Weight: 13 oz