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 14 and 15 threadless headset systems park tool tns 15 threadless nut setter features using a durable steel driver and built in guide t