The rubber caps on your bellicon ensure a stable and non-slip stand, no matter what surface you're training on. When you purchase a bellicon rebounder, the rubber caps are already included in the price. If they ever need to be replaced, you can buy them separately. Each bellicon requires 6 rubber caps. Additionally, leg plugs are included, ensuring a clean finish to the steel legs. These are also included in the price. Please note: When replacing the rubber caps, it is advisable to replace the leg plugs as well to ensure optimal functionality.