17.5 x 13.5 x 2.75 inches

Make sure this fitsby entering your model number.
SEAT CUSHION FOR TAILBONE – Made with pure memory foam with no additives. Can be used to improve bad posture while driving or sitting for long periods.
HEAT RESPONSIVE OFFICE SEAT CUSHION – The advanced memory foam seat cushion responds to the heat of your body to mold perfectly to the shape of your bottom.