The Park Tool TNS-15 Threadless Nut Setter is used to install star-fangled nuts found on threadless headset systems. Thread the nut onto the TNS-15, insert into the fork stack, and tap it in with a hammer. Sets the starfangled nut to 15mm and keeps it straight. Long handle helps prevent pinched fingers. The TNS-15 is used for 1-1/4" and 1.5" threadless headset systems. Park ToolTNS-15ThreadlessNut SetterFeatures Using a durable steel driver and built-in guide, the TNS-15 perfectly aligns the star-fangled nut and sets it to the proper depth every time The unique design virtually eliminates pinched fingers Made in the USA and covered by Park Tool's legendary limited lifetime warranty