Threaded bit on the back of GU10 lamp holders?

[Tidy Max]

Whats it for?

If you look at the back of a GU10 lamp holder they seem to have a female thread? Looks like its about M10 size on the lamp holders i've got?

Bit nerdy but just wondering if it had any use?

 

[Stroppy]

I've often wondered that too! I reckon they are universal parts which are also used in wall lights or ceiling lights which are attached to the fitting at the back.