Small 3v9 0.5W Zenner diode. Smaller than standard just 3mm.
The "BZX79C3.9 C3v9PH 0.5W Zener Diode premium quality Small (10 pack)" would be suitable for applications requiring high-quality, reliable, and stable Zener diodes in small packages, such as power management, charge pump, and buck-boost converters circuits.
