This motorized system is designed for awning windows and skylights that weigh up to 90 lbs. Using a standard 110 volt household current, the Marvel system allows operation of multiple units from one control switch. No transformer is required. A durable double-link chain opens windows and skylights up to 9.5". Marvel Motorized Operators come with mounting brackets that secure the operator to the center of the window, making this system one of the easiest to install. The Marvel system is designed to work on windows with properly-sized counter-balance hinges. ANSI/UL 325 and CAN/CSA C22.2 certified.