This plastic molded 3-1/2 in basket strainer comes with a stainless steel spring-loaded center post. Comes in multiple colors to match the color of your sink. Kitchen sink strainer installs from above the sink. Center threaded ferrule draws top and bottom flanges together and will seal water in sink. No need to reach "hard-to-find" nut under sink - it's easy to install. Mountain Plumbing Products Basket Kitchen Sink Strainer, 3-1/2 in Nominal, 3 in Overall Height, Molded Plastic, Matte Black, Import