The characteristic of this model . 1,This model is our company new designment,the special designment is the head has the place to add the grease that for piston.Traditional machine needs to open the machine to add the grease. 2,The machine is 3.0Kgs,it is lighter than other same power machine. 3,The power is much stronger,the actual input power is 850W. 4,The piston,the rotator is biggger size than other same power machine. Model no.:2803 Max Drilling Dia:28mm Input power:850W No load speed:0-1350min-1 Impact Rate:0-6000min-1 Weight:3Kgs