100 pieces thread spool savers are designed to keep thread ends tidy and prevent spools from tangling, while providing an appropriate hold to maintain thread tension. Reusable silicone design Made from flexible silicone that always returns to its original shape after removing from spools. Can be adjusted to fit different spools after repeated use. Very durable for years of use. Spacesaving and organized Thin and unobtrusive design that creates no space issues in a thread rack or case. securely holds thread spools to prevent tails from unraveling and losing tension. Easy way to keep spools orderly and ready for use. Flexible fit for various spool sizes flexibility silicone that can twist to fit various sizes of home sewing and embroidery thread spools. Note: not suitable for commercial, industrial or jumbo size spools. Usage and compatibility Function: wrap or slide the saver around the spool to hold the thread tail and maintain tension. Compatibility: suitable for most home sewing and embroidery thread spools; not suitable for jumbo or larger industrial spools. Use scenarios After finishing a project, place savers on remaining spools to prevent unraveling during storage. In a busy sewing room, keep thread tails secured while swapping spools to improve workflow. In travel or portable sewing kits, maintain organized, tangle threads on the go.