I got a Corsair 5000D airflow case from a friend for free but it is missing all the four screws that hold the side panels on the back. All the screws I can find on the internet are the short version that don’t have enough reach.
This screw is from my own PC case.
Edit: image with the short version that I was talking about
Send an email to Corsair support and ask if you can have / buy some screws. They’ll probably just send you some. Worst case they can for sure tell you the length you need.