ANTI CLOGGING STRAINER: Compared to regular bathroom sink stopper, our pop-up sink drain strainer stopper designed with an anti-clogging basket filter, to collect hair jewelry dirt to avoid clogging, easy to clean up.WATER LEAKAGE PROOF: Push button operation, a simple push on the pop-up head to open or seal the drain stopper, smooth and convenient. Thickened stepped silica-gel gasket, no glue needed, oxidation resistance and leakage proofing. (Note: Without Overflow )PREMIUM MATERIALS: Our Wash Basin Drain Strainer Stopper, constructed with thickened 304 stainless steel and brass bounce core, superior finish, anti-corrosion and rustproof, solid and durable, built to last. Exceptional quality, can be pressed more over 10000+ times.35MM DRAIN FILTER: Fits sink drain hole with an inner diameter of 1.34 to 1.39 (34mm to 35mm). Ideal for sinks with overflow. If your drain hole inner diameter is 1.45 to 1.50(37mm to 38mm), please choose 38mm drain filter. If the drain hole inner diameter is not within the size mentioned above, it will not fit and please do not buy. NOTE: please double-check the size/diameter of the sink drain before purchase EASY TO INSTALL: Simple construction for easy installation. Just take out the old one and insert the new pop-up drain filter to complete it. No tools needed. You can do it by yourself.