The KRK KNS 1/8 Inch to 1/4 Inch Screw In Headphone Adapter attaches to KRK headphone cables to convert the 1/8 inch end to a 1/4 inch. This high quality adapter securely attaches to the 1/8 inch end by screwing in. For use only with headphone cables with threads on the 1/8 inch connector such as the KRK headphone cables.