Enhance stability and security when placing a Classroom Basics Modular Charging Cabinet on a shelf, desk, or our Modular Teacher Easel. Constructed with a sturdy steel galvanized steel stem and grippy rubber pads, they also let you fine-tune the height of each foot to compensate for an uneven surface when needed. Simply insert them into the threaded receptacles on the bottom of the cabinet normally used to attach cabinets when stacking.