General description Bell glides are designed to replace the rolling casters on office chairs, converting them into fixed chairs without compromising height. This set includes 20 pieces of bell glides, making it a practical solution for stabilizing various types of chairs and stools. Technical specifications Overall Glide Height: 2 inches Insert Stem Dimension: 7/16 x 7/8 inch (11 x 22 mm) Bottom Width: 2 inches Material: PU and metal Color: Black, Gray Package Contents: 20 x Fixed Casters Measurement Allowed Error: +/- 1-3 cm Usage Can be used as fixed casters on wooden, metal, and tubular metal chairs, furniture, and other equipment.