Universal Size: This sink stopper is a universal stainless steel product with a spring core, suitable for various types of sink drains. The strainer's inner diameter is 33mm. Fits drain holes with an inner diameter of 34-38mm. Easy to Install: No tools required! It can be easily installed by hand. Simply remove the old bounce core and install the new one. Anyone can install this pop-up drain due to its simple structure. For larger diameters, use the rubber ring we provide to increase the inner diameter of the sink stopper. Premium Material: These drain plugs are primarily made of high-quality and thickened copper – durable, rust-proof, and crack-resistant. With excellent bounce and rebound resistance, water drains and closes quickly. Built-in Strainer: The sink stopper features an anti-clogging basket inside, which collects hair and prevents backups, providing effective filtration unlike push-button drains. Suitable for bathtubs, bathrooms, and kitchen sinks, etc. Two-Mode Switch: The pop-up design of this drain strainer changes the inconvenient way of draining. It's a 2-in-1 bathtub stopper and filter. Simply press down gently on the top cover to switch between the 2 modes, including water retention and water drainage.