These sterling silver bead tips are used to hide your crimp bead and to finish off your cord neatly. You put your wire through the hole in the middle and then place your crimp bead. You lock this in place. Now you bend the cap, so that the crimp bead is in the middle of the bead tip.
The bead tip is provided with an eye to which a clasp can be attached.
a = 1.40 mm; b = 12.40 mm; c = 4.00 mm, sterling silver