American Lubrication Equipment LM2203A-11-C 3:1 Thunder Stub Oil Pump, 1/4" (F) air inlet, 3/4"(F) fluid inlet, and 1/2"(F) fluid outlet. Reliable Design - Thunder pumps feature a patented, ice-free air motor contained in a rugged housing that is designed to withstand the harshest working environments. Fluid Compatibility: Automatic Transmission Fluid, Gear Oil, Hydraulic Oil, Motor Oil, Synthetic Oil. Free Flow Rating: 18 GPM, Working Flow Rating: 6 GPM, Cycles Per Gallon: 37, Air Inlet Pressure: 0-150 PSI. Noise Level @ 100 PSI is 80 db. Thunder's revolutionary design, inexpensive rebuild kits, and field serviceability all add up to a pump that has the lowest cost of ownership in the lubrication equipment market.