The McAlpine T28M-NRV Multifit In-Line Non-Return Valve is a plumbing component designed to prevent backflow of water or sewage in a drainage system. It is installed in-line with the pipe and allows water to flow in one direction only. The valve is made of durable plastic and features a top access for easy cleaning and maintenance. This means that if the valve becomes clogged with debris or sediment, it can be easily accessed and cleaned without having to remove the entire valve from the pipe. The Multifit design of the valve means that it can be used with a variety of different pipe materials and sizes, making it a versatile choice for many different plumbing applications. Overall, the McAlpine T28M-NRV Multifit In-Line Non-Return Valve with top access for cleaning is a reliable and easy-to-maintain option for preventing backflow in a drainage system. Available in 1.25" and 1.5" sizes Prevents back flow of water Must be installed in the horizontal position Should only be used when there is no alternative Universal Connections McAlpine T28M-NRV 1.5" Multifit In-Line Non-Return Valve in White