BATTERY GLAZER 17 - Machine can clean up to 15,000 sq feet on one battery charge. Charger is built-in and simple to use. - 17 Rotary diameter with a 1500 RPM. 17 cleaning path and a sound level of 50dB. - Unit has a dust control feature to ensure a healthier indoor air quality (IAQ). - Batteries are gel, eco-friendly. They are rechargeable and maintenance free.