FLEX professional variable speed car polishing tools provide optimum tool balance for superior control and reduced job fatigue. FLEX angle car polishers feature the unique FLEXelectronics for ease of use and improved tool performance. All FLEX electric power tools feature spring loaded FLEX Longlife™ carbon brushes. When the brushes start to wear down, a tension spring is released pushing the brushes away from the armature, resulting in a longer overall life of the product. In the case of excessive load, the tension spring will be completely released, stopping the machine from overheating.