These crimpable end caps have 6x2mm holes large enough to accomodate large stringing materials like round cords, suede lace, and ribbons. To hold materials in place use a hammer and block, tapping gently until hold is achieved, or try nylon jawed flat nose or parallel pliers! (Glue also works.) Pair them with TierraCast® Distressed Barrel Beads. The lightly hammered texture works nicely with TierraCast® Hammertone products.