The Mainstays Stainless Steel Kitchen Sink Strainer and Stopper fits most standard 3 1/2 kitchen sink drains. The stainless steel construction is durable corrosion resistant and rust proof for many years of use. The strainer requires a narrow center hold style drain for proper installation. This Mainstays strainer and stopper combo is easy to use and anti-clogging. Push and twist the center knob to fill the sink with water twist and pull to strain. Convenient and easy to clean basket. Measures 3.18 in diameter.