Amazingly quiet, high airflow PC fan. Originally paid $35. Corsair Air Series AF140 Quiet Edition Asking $25 each. One set is sold. https://www.corsair.com/us/en/Categories/Products/Fans/Air-Series%E2%84%A2-AF140-Quiet-Edition-High-Airflow-140mm-Fan/p/CO-9050009-WW