The Windscoop Ventilating Sail puts an end to hot, stuffy cabins and sleepless nights. The Windscoop is aerodynamically designed to force the slightest breeze down into your cabin to keep you cool and comfortable. All seams are double-stitched. Two battens are sewn into place. The versatile Windscoop can be hung from a halyard boom or a roller furling sheet. Fits any hatch or companion-way up to 4 feet (120 cm) wide. Nothing to install. Since the Windscoop has no tie-downs, once you put it up, it will follow variable wind. Works with most screens. Windscoop is packed in its own protective nylon storage bag. Colors vary.