Eze Breeze vertical four track units can transform an ordinary space into an extrodinary getaway in your own backyard. These panels typically have four sections that can be slid up or down to give you 75% ventilation. When the wind blows, you can slide them closed to keep out the rain, pollen, dust or snow. With this enclosure system, you can leave your furniture uncovered all winter, spring summer and fall, and have instant use of your little hideaway any time you want. The Eze Breeze units are made to fit in between your existing posts. This conversion can be accomplished in a single day. You will never love your patio more than after this conversion.