The DTD155Z is a cordless Impact Driver, with variable speed control, powered by 18V Li-ion battery to supply energy to the brushless motor to deliver up to 3,000 rpm, 3,900 ipm and 140 Nm of maximum tightening torque for a wide range of fastening applications. The brushless motor eliminates carbon brushes, enabling the motor to run cooler and more efficiently for longer life, and optimises battery energy use for up to 50 per cent longer run time per charge. The Impact Driver features 3 mode operation. Hard mode, soft mode and A-mode for a range of applications. The A-mode feature helps to eliminate "screw cam out” and "cross threading” by driving at low speed until the tightening begins. The DTD155Z has a convenient ¼” hex chuck for quick and easy bit installations and removal.