Air over oil reservoirs provide precision hydraulic power from shop air. Exact cylinder movement is achieved without the high cost of conventional hydraulic power requiring pump, motor, filter, etc. Basic circuits, when used with low pressure hydraulic check, flow control and directional valves, allow oil (driven at 1 : 1 ratio) to force piston rod at the same speed through both forward and return stroke. The speed control is adjustable to your work requirement. Standard Features: 1/8 or 1/4 inch NPTF air inlet 1/4-20UNF for mounting 1/4, 3/8 or 1/2 inch NTPF fluid outlet Temperature and Pressure Ratings: Maximum working temperature: Polymer up to 140°F (60°C) Aluminum up to 250°F (121.1°C) Maximum working pressure: Polymer up to 80 PSI (552 kPa) Aluminum up to 125 PSI (861.9 kPa)