Featuring the latest Ballasted Wind Gate (BWG) technology, Aer-Flo Tuffy Ballasted Windscreen automatically opens to allow high velocity winds thru . . . NO MATTER THE DIRECTION OF THE WIND. It helps to protect chain link fences from wind damage. HOW DOES IT WORK?Individual 5 ft. wide Ballasted Windscreen units are attached to chain link fence only along their tops, and the units are installed alternately on both sides of the fence. The bottom of each section has a sand-filled PVC pipe inserted thru its entire width in a triple-reinforced pocket. This bottom weight is engineered to provide just the right amount of ballast to hold the weighted windscreen unit in a vertical position during lighter, tennis-playable winds, but it automatically opens up to let higher velocity winds flow thru, significantly reducing wind stress on the fence. SINCE HALF OF THE WINDSCREEN UNITS ARE ON EACH SIDE OF THE FENCE, HALF OF IT OPENS UP NO MATTER THE WIND'S DIRECTION. This is our revolutionary solution to the age-old problem of high winds damaging fences due to the sail-like resistance of fully-attached windscreen.Self Tie-Up feature: Built-in hook & loop strips at top allow one person to roll up and secure entire unit in less than 30 seconds. SAVES COSTLY LABOR TIME. Also, windscreen orders are made to order so as an estimate please allow for 10-12 extra business days plus transit time for delivery.