RS Pneumatic Actuators Indicator Hardened alloy steel pinion Actuator Body: Aluminium extrusion is hard anodized (over 30um) to protect against wear and corrosion while reducing piston friction to the absolute minimum End Caps: Epoxy coated Pistons: Fitted with high quality rings and guides Travel Adjustment: The standard adjustment is ± 5°in both the open and closed positions High Performance Springs Bearings and Guides NBR O-rings