Car Flexible Pipe Diesel Particulate for BMW 1, 3, 5 Series E81 E91 316d/318D UK. This unit is made of stainless steel with an inlet diameter of 50mm and outlet diameter of 55mm. It has a body length of 200mm and features a clamp-on connection. The manufacturer part number is HCOZU7, and it fits various BMW models. The product comes with a 2-year manufacturer warranty and includes one unit in the package.