Propane-like performance. A smart motor controller monitors the battery pack and keeps the pad speed constant as the batteries wear down. As you shine the floor, a 99.5% efficient filter bag cleans the air exhausted from the burnish shroud. The pad driver lifts to allow for simple pad changes from a standing position. Quiet enough for day time use. A clean alternative to propane, the Charger battery burnishers produce no carbon compounds while burnishing. Efficient dust collection maintains your indoor air quality.