Invacare Tracer SX5 Wheelchair, 20" x 18" w/ Full arms, Swing-Away Leg Rest, Anti-Tippers, and Pull Wheel Locks Featuring a carbon steel frame, a heavy-duty inner liner to keep the seat and back from stretching and urethane rear tires mounted on "no flex" wheels, the Tracer SX5 Wheelchair is built to last. Dual-axle allows for conversion to hemi-height.