 option ensures operation even during a power outage i had hobbs door service technicians replace my noisy home door opener with a quiet lift master unit and upgrade the old rollers in my door with ultra quiet urethane rollers hobbs door service has called tidewater home for nearly 60 years give them a call 757-467-8002 757-467-8002 or at hobbsdoor.com that's hobbsdoor.com