美国进口BOOKIN博金聚氨酯圆带PR90系列BOOKIN博金聚氨酯圆带型号圆带直径抗拉力强度N延伸率%***小轮径PR90227.7512PR903317520PR904425530PR905540540PR906665550PR907796555PR9088120565PR909.59.5170585PR9012.512.53005125PR9015154305140PR9018186305190PR9020207805250)