1.Special selected Spring Wire 2.Withstand wind up to 117Km/h 3.UV ... a best and most economic option for greenhouse film fastening system, with our well designed Lockup steel or aluminum proifle, 2 ... 120 km/hour wind. It is made of high tension Spring steel wire, can be used many times Without distortion. UV ... Dia2.0mm,2.2mm,2.3mm,2.5mm Wiggle Wire Spring For Greenhouse