Park Tool Threadless Star Nut Slide-Hammer Description: The TNS-4 makes for a quick and simple install of the star-nuts used with 1" and 1-1/8" threadless headsets. The durable steel driver and built-in guide perfectly align the star nut and properly set the depth every time. Designed for years of everyday shop use. Features: Uses a built in slide-hammer guide for installation of 1" and 1-1/8" star nuts Proper star nut alignment and depth every time Replaceable set screw #822