The right side fork leg on OEM Harley inverted forks features a special castle nut to secure and compress the fork spring. This solid steel socket helps to remove and install this special nut. Works on 2018 to present FLSB Sport Glide, 2019 to present FXDR, 2018 to present FXFB & FXFBS Fat Bob, 2016-2017 FXSE Pro Street Breakout, 2012-2017 VRSCDX Night Rod Special, 2009-2017 VRSCF V-Rod Muscle, 2016 to present XL1200CX Roadster and 2008-2010 XR1200.