Proportional hydraulic flow control solenoid valve for Caterpillar E330C and 330D excavators. Part 225-4558 (KWE5K-31/40E30-116A) features 24V operation with Yellow Dot marking. Provides precision variable flow regulation for travel motor control, implement speed modulation, and auxiliary hydraulic circuits, delivering optimal hydraulic system performance and improved fuel efficiency on heavy-duty applications.