This tapered #7 Rubber Stopper is the perfect size for sealing 3.0 and 5.0 gallon glass carboys. It has a 9 mm hole in the center, for use with an airlock or tubing.
Top Diameter: 37 mm
Bottom Diameter: 31 mm
Length: 24 mm
WARNING: This product can expose you to chemicals including Ethylene Thiourea, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information, go to www.P65Warnings.ca.gov.