Victoryun Modern Contemporary Mechanical Gear Wall Clock with Calendar Wheel Decor (Silver) All gears are made of plastic and the main unit is made of steel. Several small gears are running nonstop 24 hours a day to initiate the movement of the outer big gear. It shows time at the default "12 clock" position. Read the date and month on the 2 little wheels on the center and the time on the large 22 inches wheel. Month wheel rotate manually once a month. Date and time rotate automatically. Good quality with marvelous design which delight your home & office.