The McAlpine S9 Pushfit BSP Screwed Overflow Adaptor is a plumbing fitting made by McAlpine that is used in overflow systems. The "Pushfit" designation indicates that the fitting is designed for easy installation and can be pushed into place without the need for additional tools or sealants. The "BSP Screwed" designation refers to the type of threading on the fitting, which is designed to connect to other components with BSP threading and has a screwed connection design. The "Overflow Adaptor" describes the purpose of the fitting, which is to connect an overflow pipe to the rest of the plumbing system. Overall, the McAlpine S9 Pushfit BSP Screwed Overflow Adaptor is a specific plumbing fitting that may be useful in certain applications where an overflow pipe needs to be connected to a larger plumbing system, and where a screwed connection design is desired. Its pushfit design makes installation quick and easy, and its BSP threading allows it to connect to other plumbing components with the same type of threading. ・ Available in 1¼" and 1½" sizes