Brass Folding Crimp Ends, Fold Over Crimp Cord Ends, Nickel Free, Red CopperSize: about 5mm wide, 13mm long, hole: 1mm, inner: 4mm.The folding crimp ends fit up to insert about 4mm cord or ribbon.â Easy to Use: Lay the ends of the cords in the folding crimp ends; use a plier to press down the sides at a time to fix the cord ends tightly on the metal crimp end caps. Finally, attach it to a lobster clasp with a jump ring.