The G2 Handlebar Tap prepares your handlebar for using G2 Threaded Handguard Mounts or G2 Billet Grip Protectors (both sold separately). "Most Aluminum Handlebars:" Includes 5/8x11 UNC carbon taper tap and aluminum guide keep the tap centered perfectly for easy thread tapping. Fits most aluminum handlebars. Note: NOT for use with Renthal Twinwall or late model YZ/YZF models. "Renthal Twinwall / Current YZF/YZ/WR Stock Handlebars:" Includes 11/16x16 UNS carbon taper tap provides easy thread tapping for aluminum handlebars. For use with Renthal Twinwall and the following Yamaha models: YZ250F (2019 and newer). YZ450F (2018 and newer). YZ250FX (2020 and newer). YZ450FX (2020 and newer). WR250F (2020 and newer). WR450F (2020 and newer). YZ125 (2021 and newer). YZ125X (2021 and newer).