This is a package of 3 buna gaskets for tri-clamps.
Use these gaskets to fit ferrules with 2″ OD. This ferrule size is commonly used with both 1″ and 1.5″ ID tri-clamp fittings.
These are the very same gaskets you will find on BrewMagic equipment with thermometer connections.
Sold in packages of 3. For example, ordering quantity of 2 will give you 6 gaskets.