Twin Trapezoid Vented Sled
[trapezoid] (quadrilateral, four sided) with no parallel sides.
Ed Grauel applied his experience and skills to Allison's / Scott Sled kite and improved the vent design that Scott had utilised. The use of twin trapezoid vents refined the kite and made it much more stable. The Sled relies on the wind pressure to maintain it's shape and can collapse if hit by cross-winds. The twin vents force high-pressure air from below the sail into the turbulent airstream above the sail, serving to stabilise the Sled's flight.