Park Tool TNS-15 Threadless Nut Setter
The 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.