SIZING: Small Size has inside diameter of 1/4” (6.07mm) for US needle sizes 0 to 8. SOFT & FLEXIBLE SNAG-FREE DESIGN: Unlike hard plastic markers that can be brittle or uncomfortable to work with, our markers are made of a soft, flexible rubber. They are seamless and have no sharp edges that catch on delicate fibers. They move easily with your yarn unlike silicone markers that ares sticky/tacky. They move easily and won’t interrupt your flow.