The height property sets the height of checkbox and width property sets the width of the checkbox. Note: The plain prop has no effect when button or buttons is set. HTML | DOM Input Checkbox disabled Property. The height property sets the height of checkbox and width property sets the width of the checkbox. The plugin uses Bootstrap markup and CSS 3 styling by default, but it can be overridden with any other CSS markup. size: string: null: Size of the toggle. Find the Bootstrap checkbox that best fits your project.