Heavy service grease pump packages - 50:1 and 100:1 Ratios Thunder Series 2"50:1 Ratio 2" Diameter Air MotorThunder Series 3"50:1 Ratio 3" Diameter Air Motor425 Series50:1 - 100:1 Ratio 4-1/4" Diameter Air Motor600 Series13:1, 23:1, and 46:1 Ratio 6" Diameter Air Motor