Noctua's fabled 200 mm A-series fan is closer to market availability, with the company greatly refining its design. In its latest prototype, the fan features a new fiberglass impeller. Fiberglass is chosen over ABS plastic as it is 26% lighter. A 200 mm ABS plastic impeller would need greater torque on the motor to get going at acceptable speeds. The motor features a larger 4 mm-dia chrome-steel axis (33% more bearing surface), and SSO2 ball bearing. Other features common along Noctua fan prototypes, such as acoustic optimization along the frame, a stepped inlet design, and vibration dampening pads are carried over.