The perforated bushing is tape welded, unlike the all-metal one of the similar Mann (I also use Mann, I have one in stock, I wanted to buy a couple more in reserve, they went up a lot, . and then an inexpensive Chinese Mahle turned up). The welded sleeve is made to reduce the cost. Some perfectionists argue that a perforated sleeve made of a solid pipe is more reliable and durable than a welded one . I don’t know, who would tell in which parrots and why measure these great reliability and durability? . The filter either meets the specifications or not. So perfectionism, . that's it . I'm just for information. And I have a pepelats Ford Kuga 2.