This invention relates to an apparatus for selective positive feeding of a plurality of yarns (Fa-Fd) to striping knitting machines, comprising a plurality of yarn feeding units (1), each having a number of yarn feeding devices. The invention proposes to use a single electromagnet (9) in each yarn feeding unit to move the yarn control elements (7'a-7'd) of all yarn feeding devices from their feeding to their non-feeding positions by means of a uni-directional coupling between the electromagnet (9) and the control elements (7'a-7'd) and to move the control elements in the reverse direction by means of an increase in yarn tension when the yarn (Fa-Fd) is being knitted into the fabric.