Polymer Products - 18 Inch Clear Acylic Globe with a 7.5 Inch Solid Flange - 18 inches in diameter, neck height is .5 of an inch and OD of flange is 7.5 inches with an inside opening of 6.5  inches. Globes are made to fit down inside an 8&quot; fitter and are held in place with set screws. Globes are injection blow molded.