Spin and seal stainless steel strainer fit sinks with a 3-1/2 inch to 4-inch opening. Constructed out of stainless steel with a 3-1/2inch flange which gives you the perfect choice for your next kitchen Plumbing project. The unique design of Spin-Lock Sink Strainer uses a twisting closure to provide a secure seal that lasts. The positive seal is very durable, and the stainless steel body construction is corrosion resistant. It prevents unwanted debris and foreign objects from slipping down the drain. Easy to Clean & install. More like the quality that would come from a professional plumbing supply.