Each End contains one screw bottom (collet) and one top cover. These are for finishing the ends of beading wire or thread, tiger’s tail, or nylon cord. They can accommodate wire/cord up to 0.019” thick (24 gauge), and can cover crimp beads/tubes up to 2mm by 2mm. These are used by inserting the end of the wire or cord into the screw bottom, finishing the wire/cord with a knot or crimp bead, and screwing the cover onto the bottom, thus hiding the knot or crimp. When closed they measure about 10mm long by 4mm wide.