The McAlpine C10A is a type of bottle trap, which is a plumbing component used to prevent foul-smelling gases and insects from entering a building through a drain pipe. The C10A model has a 75mm water seal and an adjustable inlet, making it suitable for a variety of plumbing configurations. The trap also has a multifit outlet, which means it can connect to pipes with different diameters and types of connections. The water seal in a bottle trap is created by the shape of the trap itself, which holds a small amount of water in a U-shaped bend. This water creates a barrier that prevents gases and insects from entering the building through the drain pipe. The adjustable inlet on the C10A allows it to be connected to pipes of different sizes and angles, making it a versatile option for a variety of plumbing setups. The multifit outlet means that the trap can be connected to pipes with different types of connections, such as compression fittings, solvent welds, or push-fit connections. Overall, the McAlpine C10A 75mm Water Seal Adjustable Inlet Bottle Trap with Multifit Outlet is a useful plumbing component for preventing foul odors and insects from entering a building through a drain pipe. Its adjustable inlet and multifit outlet make it a versatile option for a variety of plumbing configurations. Available in 1.25" and 1.5" sizes 75mm Water Seal Multifit Compression Outlet suits all plastic, copper and lead pipe Adjustable Inlet makes trap suitable for all domestic repair, maintenance and improvement work Manufactured in polypropylene McAlpine C10A 75mm Water Seal Adjustable Inlet Bottle Trap with Multifit Outlet 1.5" in White