This Listing is for a set of 4 METAL BASE Glides that fit Herman Miller H Base Stacking Chairs with 5/8” OD and 7/16" ID Tube Legs. Mallet not included. ALSO ALAILABLE WITH NYLON BASE HERE. SEARCH EBAY ITEM NUMBER 303791916040These fit the older chairs with the leg having 7/16" Inside Diameter. A more durable replacement solution to the original design. If you are unsure as to fitment to your Chair, please send questions with photos of your chair and I will do my best to determine what is right for you.