1.6 inches large size. This drain stopper is big, round, and flat, easier to work with different size holes: tub, bathtub, kitchen sink... 2.Good heavy silicone material. It will not slip around like cheap plastic stoppers do. Great suction and easy removal. Its easy for us to lift up but adds enough complexity for a kiddo. 3.Save water. This tub stopper prevent leakage, which has made doing dishes or giving your kids a bath 10x easier. Especially use it in the winter to slow down the draining of hot water in the shower, helps to keep the shower and bathroom a little warmer. 4.A quick inexpensive fix to unpleasant smells emanating from the drain. 5.must have for your travel. Especially to foreign countries where the sink stoppers hardly ever work making clothes washing a trick.