Spare fly sheets.  Own a Rev Pick-Up Truck Tent and want to use your Rev Tent on the ground with more weather protection than the inner tent offers?  Get a spare fly!   Want a different color?  Different features?  Get a spare fly!  

The Hellastorm offers an extra door layer and a whooping 3000mm P/U of top to bottom waterproof protection.   

DOES NOT INCLUDE TENT.  This is just the outer layer!