Check the listing for details. 0.98"x0.98" Caster Insert with Thread Square Furniture M8 Thread , 4Pcs. Condition: New. Listed at 14.83 USD. Caster Insert with ThreadDescription:★Material: Plastic; Inner Height: 13mm/0.51"; Overall Height: 17mm/0.67"; Thread Size: M8*1.25; Overall Size: 25x25mm/0.98"x0.98"(LxW); Package Includes: 4 x Threaded Tube Inserts (Does Not Contain Adjustable Leveling Legs)★Easy Installation: The chair leg plug comes with ribs, only requiring lining up with them before tapping it into position. Note: It will be a bit tight during installation. You can choose a size that is 1-2mm different from the installation diameter or put them in boiling water to soften them before installation.★Effect: The thread tube plug can choose caster installation for easy movement; choose adjustable feet for balance, protect the floor, and be anti-skid and noise reduction.