Features: Large displacement-design. Insect, pest and rodent-prevention, odor-control. The cover opens when draining. When it is not draining, the cover closes tightly to block peculiar smell. Large flow direct discharge, drainage-gravity is transformed into centrifugal force to accelerate drainage and sewage. Can be used with floor drains in bathrooms, bathrooms, basements and laundry-rooms. Plug and play design, simple and convenient installation, no need to change the existing floor drain. Specifications: Material: Plastic Size:As Picture Shown Use Pipe Depth: ≥60cm Floor Drain Diameter: 3.9-4.5cm Note: ①.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. ②.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thanks for your understandings. Package includes: 1x Drain Backflow Preventer(other accessories-demo in the picture is not included.) Large displacement-design. Insect, pest and rodent-prevention, odor-control. The cover opens when draining. When it is not draining, the cover closes tightly to block peculiar smell. Large flow direct discharge, drainage-gravity is transformed into centrifugal force to accelerate drainage and sewage. Can be used with floor drains in bathrooms, bathrooms, basements and laundry-rooms. Plug and play design, simple and convenient installation, no need to change the existing floor drain.