See Littelfuse Commercial Vehicle Products Products
Zener Diode - JANTX Level - 3.9V - ±5% - 500mW - 20 Ohms - 2 µA @ 1 V Reverse Leakage @ Vr - 1.1 V @ 200 mA Forward (Vf)(Max) @ If - DO-35 (DO-204AH).