QUIK RELEASE JOINTS - are they all the same??

[jockey]

purchased mcdermott cue with quick release joint, did not get jp's with cue.
after looking through several internet stores, i'm led to believe not all quick release joints are same?
however - spokesperson from J&J tells me "universal fit".
Lucasi, Viking and McDermott tell me thier quik release joints cannot interchange?

 

[cueman]

They are not all the same.

 

[jockey]

i'd like to know, the predator unilock and the mcdermott quick release, are they compatible?
can predator unilock interchange with mcdermott quick release?

 

[KJ Cues]

Ah.......No.