The Spectra Duckbill Valve Set is designed to increase suction and provide better output during Breast Pumping sessions while preventing backflow contamination. Each duckbill valve is one-piece making it easier to clean and lasts longer. Spectra Duckbill Valves are made of silicone and quality tested to ensure a sturdy grip on small, medium, large, or x-large breast flanges. All Spectra Breast Pump parts that come in contact with Breast Milk are BPA/DEHP-free. Authentic Spectra Duckbill Valves are specifically designed for Spectra Breast Pump parts: establishing a proper connection to achieve best performance and quality pumping sessions. The Spectra Duckbill Valves Set comes with two white duckbill valves. If you have questions or issues with any Spectra product, please reach out to our Customer Care team before contacting your original place of purchase. We will happily assist anyone with all questions at 1-855-405-0993.