Hot Start Nut for FCR Carburetors.CNC machined from 6061-T6 aluminum.Anodized finish in Blue, Red, Green, or Orange.Features a 10mm hex head for installation and removal.Direct replacement for the hot start nut on FCR carburetors.Compatible with YZ250F, YZ450F, WR250F, WR450F, WR400F, WR426F, YZ400F, YZ426F.Also fits CRF150R/RB (2007–2024), CRF250R (2004–2009), CRF250X (2004–2017), CRF450R (2002–2008), CRF450X (2005–2017), KX250F (2004–2010), KX450F (2006–2008), KLX450R (2008–2019), RMZ250 (2004–2008), RMZ450 (2005–2008), RMZ450Z (2005–2007), and select KT.M models including 250 EXC/SX-F/MXC (2005–2010), 450 EXC/SX-F/MXC (2003–2010), 525 EXC/SX-F/MXC (2003–2010), 450 SMR (2010–2012), 450 SX-F (2007–2012), 505 SX-F (2007–2008), 505 XC-F (2008–2009), and 505 SX ATV (2009–2012).