50Mm Fan 5V USB Brushless DC Cooling Fan, 4 Pack Speed 4200 RPM Fan for Small A

Airflow: 3CFM, Speed: 4200±5%PRM, Noise: 22 DBA. Oil Bearings 5010 5V DC Blower Fan. Speed: 4200±5%PRM. Maximum rotational speed 4200 RPM. Max Rotational Speed 4200 RPM. Bearing Type: Oil Bearing; Lead Wire: USB; Length: 1m / 39.37 in.