2-Speed Crank upgrade kit for Eco-Tads Includes FSA Patterson 2-speed crank, shifter, cable, cable guide and grips Planetary gear system with 1.6:1 overdrive ratio, 28t sprocket yeilds 28/45t External bearing Mega-EXO BB included Brushed alloy 170mm crank arms Q-Factor of 172mm Eco Tad 2-Speed upgrade kit