There are a few places I need to check, but so far I have had no luck.
I have seen industrial heavy versions of these in a hardware store but I want small ones designed for 19 inch racks for musical effects. The computer market - I saw plastic things similar but not suffice:
And I could not find a Chinese translation of this as most people have no idea what they are called. A Chinese translation may well bring up some results on say ruten.