A flexible rubber adaptor coupling is used to connect two pipes or pipe fittings that have different outside diameters or are made of different materials. This coupling allows for the connection of pipes with varying diameters, making it versatile for different plumbing and drainage systems. It provides a secure, airtight, and watertight seal, ensuring there are no leaks. The flexibility accommodates minor misalignments or movements between connected pipes, useful in systems that may shift or settle. Installation is quick and easy using simple tools. These couplings are commonly used in residential and commercial plumbing, as well as drainage systems. Specifically, the MAC 0502 model is 40mm - 50mm to 32mm-40mm, designed for above and below ground use with an external compression seal, resistant to 0.6 Bar.