The McAlpine R6 ¾" Straight Female Overflow Coupling with fixed nut is a plumbing component designed for use in overflow systems. It is commonly used in toilet cisterns to connect the overflow pipe to the cistern, allowing excess water to flow out of the cistern and prevent overfilling. The coupling has a ¾" female thread on one end, which connects to the overflow pipe, and a fixed nut on the other end, which secures the coupling to the cistern. The straight design of the coupling allows for a direct connection between the overflow pipe and the cistern, without any bends or angles. McAlpine is a reputable manufacturer of plumbing products and is known for producing high-quality components that meet industry standards. The R6 coupling is made from durable materials that are resistant to corrosion and wear, ensuring a long service life. Overall, the McAlpine R6 ¾" Straight Female Overflow Coupling with fixed nut is a reliable and easy-to-install component that is essential for proper functioning of toilet cistern overflow systems.