Coflex Deep Cup Fit All Sink Basket Strainer- Easy Press Basket with ball bearing closure-Chrome Premium Grade 304 Stainless Steel Body and Brass Nuts, guaranteed not to rust. 1 1/2 " Brass Lock Nut is easier to tighten than conventional 3 1/2 " metal lock nuts. Ball bearing closing feature-basket sits slightly above sink drain when opened and seals closed when pushed down. Foam gaskets included eliminate need for plumbers putty to install. Fits All 3 1/2" drains on Stainless Steel , Composite Granite, Natural Stone Sinks with thickness of up to 7/8". Works great with Snappy Trap Drain Kit.