Pro Taper Kawasaki KX250F (04-09)/KX450F (06-08)/KLX450R (08-09) Twister Throttle Tubes Twister's sealed ball bearing virtually eliminates friction Both tubes feature nylon sleeve bearing on inboard end Both tubes feature precision CNC machined aluminum tube All twister throttle tubes include a free insert for all Pro Taper bars Inside of Aluminum throttle tube is Teflon coated for smooth operation