Jack Wolfskin says about the Floorsaver Star Tunnel II
The FLOORSAVER STAR TUNNEL II groundsheet tarp protects the tent floor from damage caused by sharp stones and twigs. As a result, it significantly extends the lifespan of your tent.
The tarp, or footprint, is slightly smaller than the tent floor to prevent rainwater collecting between the floor and the tarp. The FLOORSAVER is quick and easy to attach to the tent's guying points using the elasticated loops.