An adjustable fastening mechanism generally including an adjustable clasp and a cord. The adjustable clasp has an inlet end, a fastener end, and a center core therebetween. In the preferred embodiment the adjustable clasp has an inlet and a radial port which are connected by a conduit. The inlet end of the adjustable clasp is narrower than the fastener end of the adjustable clasp. A helical groove is provided on the exterior of the adjustable clasp and extends from the radial port to an exterior bore near the fastener end of the adjustable clasp. The exterior bore extends through the solid center core of the adjustable clasp and is substantially perpendicular to the center axis of the adjustable clasp and helical groove.