A modular flow control sets the speed of the function without any extra plumbing. Bolt it into the stack and adjust.

Meter in or meter out?

Meter out restricts the oil leaving the actuator. This is the one you want on any load that can run away — lowering a boom, a vertical cylinder, a motor driving something with inertia. The oil on the outlet side does the holding, so the movement stays controlled.

Meter in restricts oil entering the actuator. Slightly more efficient and perfectly good on a resistive load that always pushes back, but it gives no control at all on an over-running load.

If you are unsure, choose meter out. It is the safe default and the one that behaves predictably when the load helps rather than resists.

Modular valves stack. Each plate you add makes the assembly taller, so the mounting bolts must be longer — the bolt length in the table is what that single plate adds. Add up your stack and order the matching SHCS bolt set; they are not included.