Overall flow height: 2 inches total float top when installed, suits for many small chair casters; This stool office chair bell glides can convert office chair with casters into a desk bound chair without wasting the chair height. Dimension of insert stem: the standard 7/16 x 7/8 inch (11 x 22 mm) grip ring mounting stem to connect to most traditional chair or stool bases, Suitable size can meet your needs; Please measure your size purchasing. Bell glides size: those bell glides are 2 inch in bottom width and a pair of inch general drift height, such as most small chair casters. Practical design: with stable PU structural glides design, can handle more weight on most of table chairs, workshop chairs or some other stools, etc., black peak with grey bottom can also smooth to check varied chairs. WILDLY USED: It can be used as the stationary castors on wood, metallic and tubular steel chairs, furniture and other package to constant them well. Colour: black, grey Material: PU, metallic Size: about 52mm Package Contents: 5 * Fixed Stationary Castors Only the above package content, other merchandise should not included. Note: Light and diverse reveals can cause the colour of the thing within the picture just a little diverse from the genuine thing. The size allowed error is +/- 1-3cm.