A bathtub drain stopper is just what the name implies—a device that plugs the drain in your bathtub, allowing your bathtub to hold water. When you are done bathing, you lift this stopper to let the water drain back out.
The simplest type of bathtub drain stopper is a rubber plug attached to a metal chain. Most hardware stores sell these rubber stoppers for only a few dollars. But most modern bathtubs come with one of two types of simple mechanisms that pull out the stopper for you.
Drain Stoppers With Trip Levers
In a "trip lever" type of bathtub drain stopper, the drain stopper is attached to a metal arm that stretches from the underside of your drain stopper and partway up inside the wall of your tub, to a switch located just under your bathtub faucet. When you flick the switch up, the arm lowers, which pulls the stopper snugly against the drain, closing the tub. To open the stopper, you flick the switch down, which forces the stopper back up.
Drain Stoppers Without Trip Levers
These bathtub drain stoppers are similar to the plain rubber plug, except you cannot remove them from the drain entirely. Instead, they are permanently housed inside the drain, with just enough clearance to let the water flow out of the tub. These bathtub drain stoppers usually have a small knob on top you can grasp and pull up to open the drain.