Here's what other sites are saying:
The ground cloth for the Black Diamond Squall is the best way to protect your tent from from sharp rocks and hedge your bets against wet or frozen ground.-- We always bring the ground cloth, as it's useful for more than just sleeping on; this handy rubber-coated footprint can be used to keep -- Stuff sack included
Protect the floor of your basecamp shelter with the Black Diamond Squall Footprint. This lightweight ground cloth increases water repellency and takes the wear and tear that would normally be dished out to your tent floor. Corner pole grommets make for a secure fit.
The Squall footprint is sized to fit underneath your Black Diamond Squall 3 tent to extend the life of the tent floor.
Sized specifically for the Black Diamond Squall tent, this footprint reduces wear and tear on your tent floor from contact with the ground.
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