Check the listing for details. 4Pcs 0.98"x0.98" Caster Insert with Thread FURNITURE M8 Thread. Condition: New. Listed at 14.75 USD. Description: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)Material: The tube plug nut is made of black plastic, with thread, can be fitted with casters and adjustable pads, has an adjustable height, is not easy to deform, and has more stable support.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.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.