... dia.: 0.08mm -- 10.0mm 3.Free Sample is available Door extension/tension springFeature:1.Spec: wire dia. Range: 0.08mm ... ,nickle plating,chrome plating,zinc plating,etc4.Quality:ISO90001&ISO14001quality system control5.stronger elasticity, resistant of high low temperature,long service ... .If anything can help you ,pls let me know,tks ! Door extension/tension spring