Had to get a new ‘cup’ recently. About 2.5 cm diameter and made of black rubbery plastic material it’s an important part of my small white spirit stove. It’s the moving seal for the fuel pump. If it doesn’t seal there’s no pressure, no hot meal, no coffee. Crucial!
It’s a common type of seal, found in tyre pumps, brakes and many other systems.
These seals are
