Battery Chainsaw Tool Only Model#MSA161T STIHL Quickstop Plus (Q) Chain Braking Feature - An additional, manually-activated chain brake Ematic Lubrication System - Two ramps, strategically placed in the guide bar rail, help contain the flow of oil and direct all lubrication to the sliding faces of the bar and chain links as well as the rivets and driver holes STIHL Electric Motor - Lightweight and compact, STIHL electric motors require minimal maintenance and feature low noise levels and reduced vibration Caring for Nature - Identifies its powered products that are more environmentally conscious, producing zero or low exhaust emissions, STIHL Inc. Defines "low exhaust emissions" as being cleaner than EPA and/or CARB exhaust emission standards STIHL Quickstop Chain Brake System - a chain stopping system designed to reduce the risk of injury in certain kickback situations Lightweight Portability - Great for maneuverability and extended use This system is designed to engage when the operator's right hand completely releases the rear handle, stopping the chain within one second.