SIMPLE INSTALLATION: No need tool, just take out the old one and insert the strainer core to complete installation. The plug avoids the problem of having to replace the entire drainpipe when it is difficult to buy the correct size drain plug. It saves you the hassle of replacing the drainpipe.PREMIUM MATERIAL: The drain plug is made of stainless steel and brass. Quickly seal and drain water with a single press. No worry of rust, cracking, corrosion or leakage. Perfect match with your sink.SCOPE OF APPLICATION: This drain filter is designed for the US standard bathroom sink drain. Available for sink holes in this size diameter range: 1-1/8 inches to 1-1/2 inches. The drain stopper comes with 3 sizes of rubber rings. The ring screwed into the stopper is for the 1 1/4 " drain hole; The spare small ring is for 1-1/8 inch sink hole; The spare large ring is for 1-1/2 inch sink hole. For recessed sink holes (sink holes are lower than the sink surface so that water can flow down the drain)BUILD-IN STRAINER: This bathroom sink drain stopper has an anti-clogging basket filter inside that can prevent the sewer from stuck with hairs, rings, jewelry, dirt.UPGRADED EDITION: Compared with fixed size traditional sink drain stopper, the bullet core plug is suitable for 1.1 in.~1.5 in. (28mm~38mm) dia size hole. It's more convenient to drain water compared to the rubber stopper, cause it is no need to pull it out to drain, and then press it to seal.