Rolling Step Stools are convenient and easy to use. Spring loaded casters along with a rubber ring around the base provide the extra grip needed when being used. Each step includes a rubber surface. Steel construction with powder coat finish. Easily assembles without need for tools. Meets or exceeds GSA standards. Specs: Top Step Height 14 1/2", Bottom Step Height 6 1/2", Top Step Diameter 11 1/2", Base Diameter 16". Available in Yellow, Red, Gray, or Black.