... pull power, use 7.0*12mm endless3.Material:PA/POM,metal mandril,imported music wire spring,2.5mm thick bracket.4 ... .Use for5.Life-testing is more than 10000 times.roller blindschainwhich weight < 13KG,area<18M2.Description38mm Keller ClutchPart No. ... primary business: We make and sell components and assemblies for Roller Blinds, Roman Blinds, Venetian Blinds and other window coverings operating ...