Globes are 10 inches in diameter, neckless with a minimum 3.5 inch opening and a maximum 7 inch opening. They are one piece injection blow molded with UV inhibitors. This is a custom cut and is not returnable. Please see see diagram. To request a custom opening, please enter the opening desired in the comments section at the bottom of the checkout page, or call 800-665-3594. If no custom opening is indicated, the globe will be sent with the minimum opening indicated in the description.