Used to convert a swivel office chair using casters to a stationary chair without losing chair heightStandard Stem Size B diameter x height: 7/16 inchx7/8 inch (11mm x 22mm), same stem size as most casters2 inch total slip height-similar to most chair casters. Not suitable for a chair that uses a 10mm stem wheel2 inch bottom width x 1.33 inch top widthGreat for converting an office stool or chair to a more stable style of glide or worn overhead cranes. Turn a chair or stool with wheels into a stationary one with these slides without significantly affecting the overall height of the chair. Color: Black Material: Metal + Nylon Diameter: 50mm Package Content: 5pcs * Universal CastersOnly the above package content, other products are not included. Note: Light reflection and different displays may cause the item's color to be a little different from the real thing. Measurement error is +/- 1-3cm