PRACTICAL FUNCTIONS - The floor drain filter with the automatic closing design, effectively block the bugs, ; Seal stinky smell and odor from sewage ; Prevent the drain water from backing up to the room; Anti- water leakage and overflow.UNIQUE DESIGN - The floor drain is designed in V-cup shape, which ensures draining and quicker water flowrate. Unique S-shape automatic closing design can strongly prevent backflow, the stinky smell and odor from sewage pipe, and block bugs and .APPLICATION RANGE - This item can be used with floor drain of the shower room and ,effectively block backflow, odor and the sewer.Environmentally Friendly -totally environmental-friendly material; No smell and no toxic; Safeguard health; No worry about deformation after stretching, super flexible; Ever-lasting and durable; Strong anticorrosion effect.Installation guide:1. measure precisely the internal diameter of the drain mouth, in case any inconvenience brought by unmatched size2. Measure the depth of the tube3. Install the floor drain one way valve4. Because the stickiness and softness feature of silicone, make support apart the mouth of drain grate with your hands in the first installation for the drainingcolour:blueMaterial:Silica gelsize:9.5*5cm,6*5cmPort diameter 5.5cmPackage Contents:4* Silicone Drain Backflow Preventer4* Stainless Steel Strainer 4* Stainless Steel Retaining RingOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.