Boye Interchangeable Needle System contains knitting needles that easily attach to separate cables to create circular needles and flexible straight needles. This set contains: 13 pairs of 4-inch knitting needle tips (sizes 2.75mm, 3.125mm, 3.5mm, 3.75mm, 4.25mm, 4.5mm, 5mm, 5.25mm, 5.75mm, 6.5mm, 8mm, 9mm, 10mm) with cable lengths to create 20in, 24in, 29in, and 36in (measurements are from tip to tip when connected), four stitch holders (button stops), one point gripper and a key. All contents are housed in a 3-sided zippered case measuring 7.75in x 7in (open: 7.75in x 14in) to keep items neatly organized. The clear vinyl front allows you to view the set.