Grado headphone joint

I changed the headband my grados and destroyed the the plastic joints on my headphones. There is no easy/cheap way to get new ones so I made my own.

I like the way the joints worked but in my opinion the hight adjustment is bit lose. Because of that I used 3 rubber o-ring. For looks the screw is put directly into the plastic without nut.

I am very happy the way the joint work.

Martial needed:
2x M3 hex bolt length 6mm
6x O-Ring 2,5 x 1,5 mm

For example here:
http://www.ir-dichtungstechnik.de/shop1/product_info.php?products_id=5913