A Radial menu is like a doughnut chart with an inner radius. The inner radius of the Radial menu specifies the radius separating the area filled with the items' background color on the outside from the inner area filled with radial menu's own background. The size of the inner radius can be adjusted using the C1RadialMenu.InnerRadius property. The circle in the middle of the Radial menu is the central button. The central button's default size is 28 and can be adjusted using the C1RadialMenu.ButtonRadius property.