container and cover 13 sharing an identical transverse cross sectional configuration the manner in which cover 13 is removably secured to container 9 is important inasmuch as this engagement must not only be easy to accomplish but also remain snug against accidental removal of cover 13 during the knitting process these requirements are realized by providing the outer peripheral surface of container 9 with an inward flange 17 of reduced thickness and an associated outward ledge 19 similarly cover 13 is provided around its open peripheral edge with an outward flange 21 of reduced thickness and an associated inward ledge 23 as is therefore apparent this arrangement permits cover 13 to be slidably fitted onto container 9 until the terminal end of its inward flange 17 engages inward ledge 23 and the terminal end of outward flange 21 engages outward ledge 19 the thickness of inward flange 17 corresponds to the width of inward ledge 23 similarly the thickness of outward flange 21 corresponds to the width of outward ledge 19 as seen in fig4 when cover 13 is fully engaged on container 9 both the interior and exterior wall surfaces of cover 13 and container are in smooth coplanar disposition with respect to each other this permits freely disposing yarn ball 8 within container 9 without the need of supporting yarn ball 8 on a spool accordingly yarn strand 7 is therefore permitted to be freely dispensed through aperture 15 of cover 13 without tangling in itself or with other yarn strands 7.