(BL215) Small end is 1-3/8 inches in diameter; the large end is 1-5/8 inches in diameter; and the length is 3 inches. Hardwood bungs are used to seal the opening of a wooden barrel. The fact that they are made of hardwood and are longer than their softwood counterparts, allow them to be reusable and easy to remove. Particularly desirable in barrels that are opened more frequently.