Sterling Silver Cable Thimble .021. Use to protect stringing materials from undue wear or abrasion from clasps and other sharp edged components. Use in the same way that you would use gimp or French Wire, the only difference is that the cable thimble is rigid. Do not pinch the ends completely together, the horseshoe design allows for some slack on the cord to reduce stress. Approx 4mmx3mmx1mm. The hole size is 0.021" or 0.53mm, will work with Beadalon or SoftFlex upto this diameter.