This is a Variable Rate Speed Control Valve from Robart.
This is used to vary the rate at which a pneumatic retract functions.
FEATURES: Red anodized aluminum, brushed aluminum, and brass construction.
INCLUDES: One variable rate control valve.
One instruction manual.
REQUIRES: Assembly onto kit.
SPECS: Length: 53.3mm (2.099")
Width: 14.3mm (.562")
Overall height: 24.0mm (.946")
COMMENTS: This valve has through-the-bulkhead style mounting, and controls
how fast your retracts move in both directions. Each adjustment
screw has a lock nut to hold it at a setting once it's adjusted.