Makita XRU04Z 18V LXT Lithium-Ion Brushless Cordless String Trimmer, Tool Only Up to 90 Minutes of Run Time on a Single Charge BL Brushless motor delivers up to 6,000 RPM for faster cutting Efficient BL Brushless motor is electronically controlled to optimize battery energy use for up to 50% longer run time per charge The BL Brushless Motor eliminates carbon brushes, enabling the BL Motor to run cooler and more efficiently for longer life.Adjustable speed dial (0-3,500 to 0-6,000) allows the operator to match speed to application Reverse rotation system allows operator to quickly clear trimmer head of entangled grass and weeds