The OTC Stinger air/hydraulic pump are an ideal all-around power source that develops 10,000 PSI at 100 PSI air. Product features a two-stage release mechanism, internal relief valve as well as a 3/8 inch NPTF oil port and 98 cubic inches of usable oil. SPX OTC Air and Hydraulic Pump feature an all-around ideal power source which develops 10,000 PSI at 100 PSI air. It is extremely durable and is easy to use. Ideal all-around power source develops 10,000 PSI at 100 PSI air.