Features:brand new and high qualityLarge displacement design. Insect, pest and rodent prevention, odor control.Magnetic suspension deodorization is adopted to seal the cover more closely. Effectively realize deodorization and overflow prevention, and protect family for health.Large drainage capacity, effectively prevent sewer backflow, flushing more quickly.The reducer ring can be used for flexible replacement without worrying about size.Can be used with floor drains in bathrooms, bathrooms, basements and laundry rooms.Plug and for play design, simple and convenient installation, no need to change the existing floor drain.Silicone ring has good toughness, can resist aging, and can maintain elastic seal for a long for time.Stainless steel reducing ring, durable and corrosion-resistant, can effectively prevent deformation.Product Size and Using method(as pictures shown): 1. Diameter: 35-37mm, use the product directly;2. Diameter: 37-44mm, add silicone ring;3. Diameter: 44-52mm, use reducing ring. Specification:Material: Plastic+MetalColor: Blue+RedSize: app. 5.3x4.2cm(2.09x1.65in)Quantity: 1 set Note:Transition: 1cm=10mm=0.39inchNo retail package.Please allow 1-3cm error due to manual measurement. pls make sure you do not mind before you bid.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you Package includes:1 x Drain Backflow Preventer1 x Silicone Seal Ring1 x Reducing Ring(other accessories demo in the picture is not included.)