Keeney Plumber's Spec 3.5-in Stainless Steel Rust Resistant Strainer with Lock Mount Included in the Kitchen Sink Strainers & Strainer Baskets department at Lowes.com
Kitchen Sink Drain 3-1/2 Inch Sink Drain Assembly Kit, Removable Deep Sink Strainer Basket with Sink Stopper/Sealing Lid for Home, Kitchen, Stainless Steel
Basket strainer - Brother Filtration
Huge Selection of Basket Strainers for Kitchen and Bar Sinks