Crimp covers go over crimps creating a look of a sterling bead just at the edge of your clasp. A very classy finish. Use a crimp tool to close it, or if you're REALLY CAREFUL you can try to close it with a chain nose plier. But be careful not to indent the metal, unless you like the "weathered" look!

This size covers a 2mm crimp bead nicely that has been crimped in the two-process manner with a crimp tool. You can try it with crimping flat, but part of the crimp bead may show through the seam of the crimp cover. Sometimes you can fudge!