Mercedes diesel mechanics, this specialty socket is essential for working on older Mercedes fuel injection pumps! The 33-point spline design fits perfectly on the pressure valve holders of MRSF-ERE injection pumps found in Mercedes 601, 602, 603, 605, 606, 615, 616, and 617 diesel engines. The 56mm length gives you good reach into tight spaces, and while it's a 1/2-inch drive socket, the relatively low torque requirements mean you'll typically use it with a 3/8-inch drive torque wrench. Made from durable CR-V steel, this socket stands up to professional use without rounding or damaging the delicate spline fittings. If you work on older Mercedes 250, 300, or other diesel models with inline injection pumps, this is one of those specialized tools you absolutely need for proper service. The quality feels solid, and the precise machining ensures a perfect fit that won't slip and damage expensive components. Whether you're replacing delivery valves, doing pump maintenance, or rebuilding injection systems, having the correct socket prevents costly mistakes and damaged parts. The 12-month warranty provides peace of mind, and the tool arrives ready to use. If you're tired of struggling with improper tools or need the right equipment for Mercedes diesel work, this spline socket delivers professional results and makes injection pump service much more straightforward.