Beyerdynamic MMX 300 cable strain relief

I liked the original design and it worked okay. But it was only a friction fit. 

So I did a slight change of the model and now when the part is in place, you can rotate is 90 degrees and it locks into place and can't be pulled out, unless it's rotated again.

Increased the height of the slots cut into the top part, to alow for them to clear the shellthickness of the headaset. Allowing for the part to rotate and lock against the shell