• With the duffel bag removed, the sled with poles attached, is inserted into the open zipper, then unfold. 
• One pole keeps the sled poles spread. Your sled is your frame. 
• The tent is made to be full at the back leaving room for your gear inside with you. Do that with your bivi-sack. 
• With the sleds hull into the wind you have a wind block and incredibly strong frame.
• High/low venting really works. Your breath drives the air circulation.
• The vestibule protects extra gear.
• 2.5 lbs, one short pole. Sit up, read, hang a light, get some sleep.

Same as the other but sleeps 2 and weighs a pound more.