New premium radial tractor tire inner tube with TR218 air/water stem This is a radial tube that can be used in any of the following size in either radial or bias tires sizes: 16.9-26, 16.9-28, 18.4-26, 18.4-28, 16.9R26, 16.9R28, 18.4R26, 18.4R28, 420/85R28. This tube will have the standard TR218 fast fill air liquid tractor stem. TR218 is the common agricultural stem type, it can be used for air or liquid fill applications. It has a removable core housing for fast liquid filling. This stem replaces the older liquid fill stem types.