Used to convert swivel office chair with casters to a stationary chair without losing chair heightStandard B stem size diameter x height: 7/16 inch x7/8 inch (11mm x 22mm) , same stem size as most casters2 inch Overall glide height - similar to most chair casters. Not suitable for chair which use 10mm Stem Caster2 inch Bottom Width x 1.33 inch Top WidthGreat for converting your rolling stool or office chair to a more stable glide style, or replacing your old, worn glides. Turn a rolling chair or stool with casters into a stationary one with these glides without affecting the overall chair height much.Colour: BlackMaterial: metal + nylonDiameter: 50mmPackage Contents: 10pcs x Universal castersOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.