The McAlpine WC-BP1 is a plumbing connector that is designed to connect a 3.5 inch (90mm) diameter outlet from a toilet bowl to a 4 inch (110mm) diameter soil pipe. The connector features an 'O' seal socket, which provides a watertight seal to prevent leaks. To use the McAlpine WC-BP1 connector, you would first need to ensure that the toilet bowl outlet and the soil pipe are both clean and free from any debris or obstructions. Next, you would insert the connector into the toilet bowl outlet, making sure that it fits securely and snugly. The 'O' seal socket should create a watertight seal. You would then connect the other end of the connector to the soil pipe, again ensuring a secure fit. The connector is designed to be compatible with both PVC and cast iron pipes. Overall, the McAlpine WC-BP1 connector is a useful plumbing component for ensuring a secure and watertight connection between a toilet bowl outlet and a soil pipe. It is made from high-quality materials and is designed to be easy to install and use. Available for Rigid WC Connectors, 4"/110mm Soil Pipe or Rigid WC Connectors with Plain End Outlet, and Flexible WC Connectors McAlpine WC-BP1 Boss Pipe for use with WC Connectors in White