This is a 3D‑printed aftermarket modification for turbofan designs, engineered specifically for computer case cooling fans—typically available in standard 80mm, 92mm, or 120mm sizes. By replacing the conventional axial fan blades with a turbine‑style impeller, this design retains the original fan’s mounting holes for hassle‑free installation while leveraging the turbine geometry to optimize airflow: either by increasing local air pressure or by redirecting airflow paths. It’s commonly used for personalized upgrades to computer cases and heat sinks.