Fans 4020 4cm double ball A4020B03MO 3.3V-5V case fan

4cm double-ball case fan

The 4020 model fits compact chassis where space is limited. It operates on a 3.3V to 5V supply, making it suitable for low-voltage headers. The double-ball bearing design targets continuous operation in tight builds. Buyers needing higher airflow for larger cases should look elsewhere.

3.3V to 5V voltage range

The wide input range lets the fan run directly from standard motherboard or controller headers without adapters. Double-ball construction reduces wear compared to sleeve alternatives. No PWM signal or speed curve is included, so speed scales with voltage only. Installers who require automatic temperature control must add a separate controller.