Models Vex IQ Double-reverse 4 bar lift 4 58 0 Vex IQ H-Drive Drivetrain, Chain and Sprocket 3 51 0 Vex IQ 3:1 Drivetrain 3 67 0 Vex IQ 4-wheel omnibot 2 68 0 Vex IQ 2:1 Drive Train 5 61 0