Adjustable Base Slope Corrector for Paver Pedestals by Skydeck USA snaps onto the bottom of the pedestal to easily correct slopes between 0-8%. This innovative product adjusts by simply twisting the tabs on the sides. Snap the base corrector onto the bottom of the pedestal, lay your level across the top of the pedestal, twist the tabs until the top of the pedestal is level and you’re done. The base slope corrector makes leveling your patio fast and easy!Base slope correctors also ensure that the pedestal sits perfectly upright. This is crucial for taller pedestals over 21″ to ensure a safe and stable patio.*Adjustable Base Slope Corrector for Paver Pedestals is compatible with SD-M, SD-L and SD-XL pedestals. They are required when using an SD-XL pedestal with more than one extender sleeve.