3-1/2"plain 72-168 needles Cylinder :3.5,3.75, 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 pattern feeds ... colours plus ground on the same colours.1- Various design socks 2- Heel in elastic part 3- Design in elastic part 4- Y-Heel 5 ...