Post hole diggers: It has simple build, easy to use, and easy to maintain. Which power comes from a tractor. It is the best digging choice for tree planting, fencing. The main specification of earth drill. Model PHD6 PHD9 PHD10 PHD12 PHD14 PHD16 PHD18 PHD20 PHD24 Auger Diameter(mm) 150 200 250 300 350 400 450 500 600 Power Match(HP) 35 40 40 40 40 40 50 50 50 Input Rotate Speed(rpm) 540 540 540 540 540 540 540 540 540 Dig Depth(mm) 800 800 800 800 800 800 800 800 800