Features: The Flat Plastic Ducting Adaptors ensures a smooth airflows conversion from 115mmx50mm rectangular to 4inch round ducts. Perfect for enhancing ventilation in bathrooms, toilets, and utility room, maintaining perfectly air circulation. This Adaptors works with extractors fan, tumbles dryer Vents hoses, and other Vents systems, ensuring efficient ventilation. Make from plastic, this Adaptors is designs to last in harsh conditions like kitchens and bathrooms. This rectangular to round duct connector allows easy installation into existing system. Specifications: Material: Plastic Size: about 185x115mm/7.28x4.53inch Outer Diameter: about 110mm/4.33inch Inner Diameter: about 108mm/4.25inch Package Includes: 1Pc Plastic Ducting Adaptors note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to difference between different monitors, the picture may not reflect the actual color.