Fit most Ambassador, Cochran, Douglas, Keller, Precision Furniture, Stoneyville, Tempo & many other Kitchen/Dinette swivel/tilt Chairs Top diameter of plastic insert measures 1 3/4" OD. Fit's 1 5/8" inside diameter center column. Height 4". Heavy duty Vertical grooved. All inserts have a 1" diameter center hole to accept the 1" thick steel shaft. 1-3/4" top OD x 1 5/8" ID Heavy Duty Replacement Plastic Insert Seat Post Bushing for Kitchen, Dinette Chair Swivels