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.