... , 4, 4.5,5 inch knit various sock Max speed: 320rpm 3-1/2"plain computerized sock knitting machine Feature: 1,One main feed plus five ... ,fully electronic control system4,Exclusive inner cam block system for high speed.5,Stepping motor for elastic yarn and stitch cam ... control.6,Electro-pneumatic yarn finger and cam control7,Pattern Depth up ...