Material: Plastic; Inner Height: 14mm/0.55"; Overall Height: 18mm/0.71"; Thread Size: M8*1.25; Overall Size: 20x20mm/0.79"x0.79"(LxW); Package Includes: 12 x Threaded Tube Inserts (Does not have adjustable leveling feet) Material: The tube cap nut is made of black plastic, has a thread, is adaptable to adjustable casters and glides, is height-adjustable, is difficult to deform, and provides stable support. Effect: The threaded cap can be mounted on casters for easy movement; Adjustable feet ensure balance, protect the floor, make the device non-slip, and reduce noise. Simple assembly: The chair leg cap comes with grooves that simply need to be aligned to thread it into position. The grooves guarantee a secure fit and eliminate the need for additional adhesives. Application: The nut cap is designed for office or home furniture, including mechanical devices, machinery, shelves, TV stands, tables, racks, beach chairs, desk legs, etc.