PLEASE CHECK YOUR OLD PART & MEASUREMENTS BEFORE PURCHASING, Plastic insert seat post bushing fits inside the 1 7/8" post standpipe of the chair leg base. The outside dimension of the insert (top flange) is 2 1/8" diameter. Fit most 2" outside diameter metal standpipe.
Installation tip: Insert the plastic seat post bushing first into the upright steel pipe located at the center of the 4 leg chair base before installing the swivel tilter. If you install the plastic bushing onto the swivel tilter first and its the wrong size for the upright steel pipe; It will be almost impossible to remove. Boiling the plastic insert in water for couple minutes -/+ may help the fins on the insert be more flexible to installation. Trimming the fins/rings on plastic insert with sandpaper may also help when installing. There is a thin coat of wax made onto the plastic insert from the molding process; it also acts as lubrication when installing and for the swiveling action from the swivel tilter mechanism.