Extending the definition of The Ultimate Ride™. One-Piece Side Frames TiLite builds the Aero X with one-piece side frames. We also build our rigid chairs with one-piece side frames. Other manufacturers build their folding chairs with two- or three-piece side frames that are bolted together, leading to flex, squeaks and loss of energy. One-piece side frames increase performance by reducing flex and increasing durability. Tru-Fit System The Aero X features TiLites Tru-Fit Component System - comprised of the Rigid Folding Mechanism, Adjustable Bullet Front Caster Housing and Curved Axle Plate. Instead of bolting through frame-weakening holes, Tru-Fit System components clamp directly onto the side frames. The Tru-Fit System eliminates one of the main stress points on todays wheelchairs by reducing the number of holes in the frame by 50%. In addition, the Tru-Fit System allows for infinite adjustability of its components since there is no need to line up components with pre-drilled holes. This design innovation also greatly improves the durability of the Aero X frame.