Here's what other sites are saying:
Big Agnes Tent Footprints - To extend the life of your tent floor, we recommend using a Big Agnes footprint or ground cloth. The Big Agnes footprint also enables you to pitch a lightweight, Fast Fly shelter while leaving the tent body behind. The Fast Fly configuration requires the footprint, tent fly, poles and stakes.
Big Agnes Camp & Hike Flying Diamond 4 Footprint 8.5 x 6 x 2 in 74037 TFFFD411.
Protect your Flying Diamond 4 tent from water and abrasion with the Big Agnes Flying Diamond 4 footprint. This lightweight nylon camping essential has webbing stake-outs that attach to your tent.
Lay down the Big Agnes Flying Diamond Tent Footprint before setting up your camp command post and rest easy knowing your tent floor is safe. This ripstop nylon ground cloth stops sticks and stones from tearing into your tent, and can be used with your poles and fly for a massive yet lightweight shelter on fair weather trips.
Hilleberg Kaitum 3 Footprint
Mountainsmith Morrison Footprint
$24 - $29
ALPS Mountaineering Tasmanian 2 Floor Saver
$25 - $32
The North Face VE 25 Footprint
$48 - $60
Black Diamond Ahwahnee Ground Cloth
$41 - $49
Marmot Thor 3P Footprint