Universal Size: This sink stopper is a universal drain plug with a ball core, suitable for various types of sink and bathtub drains. It fits drain holes with an inner diameter of 33mm to 40mm. Built-in Filter: The sink stopper features a filter plate design that collects hair and prevents clogs. Compared to standard push-button drains, this design provides a double filtering effect, making cleaning easier. Pop-Up Function: This drain stopper has a pop-up design. A gentle press on the top cover switches between two modes Stopper (to hold water) and Filter (to drain water). Self-Closing Drain Core: The sink stopper includes a water-activated valve that automatically opens when water is present and closes when there is no water. High-Quality Material: Made from high-quality stainless steel and all-copper materials, this sink stopper is durable, rust-resistant, and crack-resistant. The multi-layered electroplated surface ensures long-term use. A silicone ring helps prevent water leakage. Easy Installation: Pop-up drain stoppers are simply designed and can be installed by hand without tools. Remove the old drain stopper and insert the new one. Applicable Drain: Fits drains with an inner diameter of 34-40mm.