Pro Taper's Twister throttle tube is constructed from quality anodized billet aluminum. The sealed radial ball bearing and polymer bushing allow for a consistent and smooth throttle operation while a knurled grip mounting area ensures a vice-like grip bond. The Pro Taper Twister Throttle tubes are used by top-level pro teams and riders worldwide. Twister Throttle Tubes are compatible with all Pro Taper handlebars and Renthal 7/8" handlebars with the standard bearing insert. Precision CNC machined. Sealed ball bearing virtually eliminates friction. Plastic plug on end to prevent glue and dirt from getting in the bearing. Knurled finish to provide a solid bond between tube and grip. Twister Throttle Tubes are compatible with all Pro Taper handlebars and Renthal 7/8" handlebars with the standard bearing insert.