The Pinnacle Stair Lift is a battery-operated stair lift that provides more than twice as many trips compared to competing units in the event of a power outage. The Pinnacle does this thanks to a complete redesign of the standard stair lift drive train that resulted in the Pinnacle's patented Helical Drive. This Helical Drive is so efficient that is actually uses less power than a 25 watt light bulb. And thanks to this compact size of the Helical Drive, the Pinnacle is also the narrowest stair lift in the industry as well as the lightest! The Pinnacle is not available for self-installation or online order. Please call 1-800-774-2134 to order a Pinnacle or to receive more information.