[Size and Applicability]The floor drain backflow preventer plug has two colors to choose from, silver plated and copper, but regardless of the color, the outer diameter of the floor drain plug is 4.2cm/1.65in, the height is 3cm/1.18in, and the width of the bottom drain is 2cm/0.78in, which is suitable for a sewer with a hole diameter of 4cm/1.57in. .[Automatic]The sewer backflow preventer plug adopts gravity drain switch, that is, when draining, the bottom cover will automatically open with the water flow, and it will automatically close when not draining. With three-layer sealing ring, it can be well sealed, effectively preventing the entry of odor, sewage, cockroaches, mice, etc., creating a clean and sober living space. .[Smooth Drainage]The copper water drain pipe preventer valve features 90° direct drain and a large 2cm/0.78in bottom diameter drain hole, which ensures fast and smooth drainage and prevents water accumulation. .[Plug and Play]The shower drain pipe stopper is easy to install and only requires a few steps: 1. Open the floor drain cover. 2. Install the drain plug. 3. Close the drain cover without any additional tools or tile cutting. .[Selected Material]The floor drain preventer backflow plug is made of selected copper, which has good corrosion and rust resistance, smooth surface and easy to clean, durable, widely used in a wide range of floor drains, bathrooms, swimming pools, balconies, garages, basements and toilets.