The McAlpine BSW45P 1½" Centre Pin Sink Waste is a plumbing component used for draining water from a sink. The waste has a stainless steel flange with a diameter of 113mm, which is the part that sits on top of the sink and provides a sealing surface. The waste also comes with a reducer that allows it to fit a 1½" pipe, and it includes a plug to stop the flow of water. The "Centre Pin" in the name refers to the fact that this waste has a central pin that allows it to be operated by a sink's overflow. When the water level in the sink rises to the level of the overflow, the excess water flows down the overflow and into the waste, which prevents the sink from overflowing. Overall, the McAlpine BSW45P 1½" Centre Pin Sink Waste is a reliable and durable component that is commonly used in many residential and commercial sink installations. ・ Available with Black ABS handle plug or Black PVC plug with CP chain and stay ・ 1½" BSP ・ Centre pin dry fixing connection has the advantage of a quick, simple and neat installation affording a saving in material and labour costs ・ The 113mm polished stainless steel flange eliminates the problem of chrome plating deterioration ・ Manufactured in Polypropylene