1,Max drilling diameter: 20mm 2,Rated Voltage: 110v,220v 3,Rated Frequency: 50Hz,60Hz 4,Rated Input Power: 500w Max drilling diameter: 20mm Rated Voltage: 110v,220v Rated Frequency: 50Hz,60Hz Rated Input Power: 500w No-load Speed: 0-850r/min 1.The hight-power drill is trustworthty 2.Double insulated structure 3.Grease encapsulatin