Standard manual wheelchairs. The Tracer EX2 combines the design and technology of the 9000 series and incorporates it into the Tracer series.A true dual-axle position allows for repositioning the 24" rear wheels and 8" casters for adult and hemi seat-to-floor heights.Possible to interchange components with the 9000 series chairs. Meets RESNA standards in product performance.14-gauge crossbraces add strength and durability.Durable, low-maintenance, triple chrome-plated, carbon steel frame is long-lasting.Urethane rear tires, mounted on "no flex" wheels, offer superior performance.