The wire and micro bead work as a pulley system that adjust to all head sizes. First, pull on the excess wire with force to slide it through the microbead. Tension is required to achieve a proper fit. Once fitted properly, use the provided needle nose pliers to tightly clamp the microbead shut. You may also tie a knot with the excess wire. Carefully trim the excess wire close to the microbead. Watch instructional video here.