1.   A rubber plug in the handgrip of the frontal part of the housing allows the photographer to depress the shutter.

2.   Nearby engineers pushed soft rubber plugs into their ears.

3.   The cheap, over-the-counter earplugs are the most popular, with foam, silicon, and rubber plugs being the most common.

4.   Today most bathroom sinks have pop-up stoppers instead of the old-fashioned rubber plugs.

5.   It might be easier to stop a flood with a two-inch rubber plug.