Invacare’s TDX SI is the latest product in the Total Driving Experience (TDX) series. The TDX SI can climb over obstacles 3 inches high and has a top speed of five mph and a 300-pound maximum weight capacity. The TDX SI features Simplified SureStep Suspension for a front caster range of motion of 3 inches up and 2 inches down, stability assist for a smoother driving experience and Integrated Traction Control Design for up to 1 1/2 inches of climbing ability in reverse.