What is this speaker cable connection?

Spades are much better, connectivity-wise, in my opinion.
Bob

Thanks for the extra photos! The more photos the more problems we can see! They inexplicably screw a barrel over the thing, for no other reason than to hold the little red or black plastic ring. Brilliant! The spade itself, instead of being flat on both sides so it can fit in a range of terminals flares out making it both harder to fit and even harder to bend without breaking. More brilliance! Don't try and bend, anyone stupid enough to do all this other stuff is for sure too dumb to use quality metal that can bend without breaking. Odds-on favorite: Made in China. 

Looks like there's still one more barrel that should screw off. Inside near the spade there has to be something in there to crimp or solder the wire to the spade lug. If you're lucky then you can unscrew and throw that away, slide some shrink wrap insulator over the connection, and have a much improved spade lug. Still crap, but nowhere near as crappy as it was with all that other crap attached.

If you're lucky. With the brainiacs who made this though it could go either way. Could be they solder the cable into that big long tube.

Whatever. For entertainment purposes only. Should be abundantly clear by now we are well past wasting any more time with this. The worst spade lug in the history of audio has long since been unceremoniously cut off and thrown in the dumpster where it belongs. One half inch is stripped and the bare wire ends are twisted around and fastened in the terminal post.

Right? RIGHT???!

I could not use with my Arcam solo neo. It never stays there. I tried with KEF LS 50 and It did not work well. The always come off. That's the reason I have asked. 

Clip ‘m ‘n strip ‘m!  Then put on some simple decent bananas. get ones with at least 2 screws. Buy Parts Express # 091-3600 or 091-3610. Both good. BFAs are better than regular bananas. Got to be careful not to exert a shear force though, they can break off. 

If those barrels unscrew and reveal set screws holding the wire down I'd remove those ends and put these on instead.  I've used these on several custome built cables that are budget friendly.  These have a friendly angle for amp side as well as speaker terminals.  The downward angle is convenient on several speakers I have, do not put a high shear force on connections, locking and stackable and they're completely protected against accidental twist contact that could cause a short.

https://www.parts-express.com/angled-locking-stacking-banana-plug-with-dual-set-screws-poly-shell-an...