Firestone Texas Centennial Central Exposition 1936 Dallas Texas Ashtray. The diameter of the tire is about 5 1/2”. The opening for the glass insert is about 3”. The light amber colored glass insert is embossed with the words in the title. On the upper left side of the tire, the tire is beginning to look like it has a split.(photo) The underside of the tire appears to be in very good condition. Shipping is included in price. No returns.