The McAlpine VP50-100 Ventapipe 50 is an air admittance valve designed for use in plumbing systems to prevent the loss of water trap seals due to negative pressure. The valve features a dual fit synthetic rubber finger seal outlet that can fit both 3"/75mm and 4"/110mm soil pipes, making it a versatile component that can be used in a range of applications. The VP50-100 also incorporates a 2" outlet, which allows for the discharge of waste water from a variety of sources, such as sinks and baths. This is a one-way valve that allows air to enter the plumbing system, but does not allow gases to escape into the living or working space. The valve is made from high-quality materials to ensure it is durable and long-lasting. It fits 2", 3"/75mm or 4"/110mm pipe and has an air flow capacity of 16.3 l/s.