Modern spindles are typically available in high-whorl or low-whorl types. In a high-whorl spindle, the whorl sits very close to the top of the shaft, which is anywhere from 15-45cm long. A hook is placed on the top of the shaft to secure the developing yarn, and the newly-spun yarn is wound around the shaft underneath the whorl. In a low-whorl spindle, the whorl sits near the bottom of the shaft. The newly spun yarn is wound around the shaft just above the whorl. If there is a hook at the upper end of the shaft, the yarn is spiral-wound up the shaft and caught in the hook; if there is no hook at the top, then the yarn is spiral-wound up the shaft and secured with a half hitch (or more, for slippery fibers) at the top. Some low whorl spindles are notched at the top of the shaft to keep the half hitch secured, although this is not necessary. An alternate method of securing the yarn involves passing it down over the edge of the whorl, around the bottom end of the shaft, and back up over the whorl to be secured with a half hitch at the top of the shaft.