LED Diffuser 4mm even possible to get?

[The-Torrent]

istg its not possible to get a 4mm thick aluminium diffuser? 6mm seems to be the minimum i can find. I know theres the aliexpress link but even thats only 5mm and its not even aluminium its plastic.

Can anyone confirm they have managed to actually find a manufacturer of 4mm diffusers or am i chasing a rainbow? And if in the uk can you send link?

Thanks.