The DEWALT DCMCS574 XR FlexVolt Chainsaw is supplied with: 2 x 18/54V 9.0/3.0Ah FlexVolt Li-ion Batteries 1 x Charger The DEWALT DCMCS574 XR FlexVolt Chainsaw has an energy efficient brushless motor for longer run time. Being battery powered, it requires less maintenance than a petrol chainsaw, and has an auto-oiling system that keeps the chain lubricated. It also has a tooled chain tensioning system built to professional specifications, this helps to ensure that the chain remains reliably tensioned during use. The chain speed has been optimised for improved torque and a chain brake stops the chain in less than one second if triggered.