The concept of footprint groundsheets is a secondary groundsheet that sits between the ground and any tent with a sewn-in groundsheet. The benefits are that it greatly reduces the chances of the sewn-in groundsheet being punctured by something sharp in/on the ground and it also prevents the sewn-in groundsheet from getting dirty (because then you'd virtually have to wash the whole tent down when you got home). This footprint groundsheet is cut to the outline of the Outwell Monterey 4 tent and is made from heavy duty, waterproof polyethylene