YKK #10 Slider use for Zipper Repair or Replace Solution. YKK #10 Slider Extra Heavy Duty is Work on zippers needing to be repaired. Also be used for jewelry art and craft works. Fit with zipper #10 Metal zipper. Replace broken or worn zipper sliders. Color may vary on your monitor. On back of the YKK slider is a number. This will say 10u. Please make sure yours does too. If any other number and letter besides 10 u, this slider will NOT work.