<p>The Pro Solar Star Series 2000 greenhouses are made of roll-formed steel frames that ensure strength, long life and durability. They have 6-foot high sidewalls and rafter spacing of 6 feet. Optional additions for the Pro Solar Star Series 2000 includes polycarbonate coverings; roof, side and end vents; roll-up or drop-down curtain systems; circulation and exhaust fans; evaporative cooling systems and more. <br /> <br /> </p>