06 Berth Cushion in place. Please note we cut the HyperVent 6 inches in circumferance larger than the Berth cushion to allow the Hypervent to extend up the sides. IMPORTANT UPDATE JULY 2012. We had to cut the excess hypervent material to just fit the berth cushion's dimensions after several restless nights sleeping. We found that the original configuration caused the berth cushion to curl up slightly along the sides, forcing us to sleep in the middle. The manufacturer's instructions were right! We now sleep soundly, with no condensation underneath the cushion.