I don't think I have ever encountered two vacuum hoses or attachments that fit together, that didn't come in the same box. When I bought my current dust extractor, a Fein Turbo-II, I also purchased this soft plastic hose adaptor. It, combined with some shameful use of Gorilla tape, has allowed me to limp along for these past 6 years. Who knows how many water-inches of suction I have lost along the way!