Prevents burn-out, stops rust and increases torque up to 25%. A compact oiler that fastens directly to the air tool. Precisely meters proper amount of oil to the tool only when the tool is in use. NO adjustments necessary 1/4 in male NPT outlet, 1/4 in female NPT inlet. Use on all 3/8 and 1/2 in air impact guns, air wrenches, body shop air tools and pneumatic hammers. Note: never use motor oil in pneumatic tool.