The high-performance Invacare TDX SP Power Wheelchair boasts superior ride quality, quieter chassis and built-in technologies that make all the difference: True Center Wheel Drive, Enhanced Invacare SureStep Suspension, Traction Control Design, Quiet Invacare Stability Lock and Invacare MK6i electronics. Center Wheel Drive Power Wheelchair G-Trac Technology available to keep wheelchair tracking straight Quiet stability lock provides stability and shock absorption while in-motion Traction Control Design for climbing in reverse over obstacles up to 1" Fully-programmable MK6i electronics for maximum control.