A cup plunger is the traditional style of plunger used for unblocking drains e.g. sink and bath drains.
Cup plunger handle
The cup plunger usually has a wooden handle.
Cup plunger cup
The plunger also has a half dome shaped head called the cup. The cup of the plunger covers the drain hole and forces the water up and down the drain (See section on Cup Plungers).
Cup plunger plastic plate
Some manufacturers may fit the cup with a plastic backing plate. This plate provides the cup with reinforcement when the plunger handle is pressed down into the cup. The plate prevents the rubber from tearing and splitting over time, as the plate spreads the force over the cup’s surface, rather than just in its centre.
