The switchable valved exhaust on my 911 had stopped working and I narrowed it down to the one way vacuum valve not working. This was the correct genuine part so bought one and it solved the problem. Is it good value for money? No! It’s £20 for a little bit of plastic BUT it does the job and is the genuine article. Could I have got a cheaper Chinese copy, undoubtedly but the last one lasted 20 odd years and so should this one.