plain, terry dual-use computerized sock knitting machine 72-220 needle Cylinder :3 ... 4 ,4.5, 5 inch knit various sock Richrui computerized sock knitting machine (3-3/4″ plain and terry ... ground or the same course.3,Drumless,fully electronic control system4,Exclusive inner cam block system for high ... 5,Stepping motor for elastic yarn and stitch cam control.6,Electro-pneumatic yarn finger and cam control7, ...