This stopper has two holes and is perfect for using with a thermowell. It features one 3/8" hole and one 1/4" hole. A racking tube or stainless tube can be inserted into the 1/4" hole with the aid of some lubricant, forming an airtight seal, and the 3/8" hole fits an airlock. Use with airlocks, thermowells, racking Canes, and more.
