Yamamura m6000 speaker cable??

Anyone who knows this cable? I've just bought it 2nd hand. What is the correct way to install it? The seller told me that the side with 3 connectors should go on the amp, but I find it strange that the arrows on the stickers point from speakers to the amp then.. All other cables I know always need to be installed with the arrows pointing from amp to speaker.

Anyone can help me?

I suggest trying the cables both ways and let your ears be the judge.
I think you are correct, and not the seller.
I used to own the same cables a while ago. the seller, if, I recall, may be correct. isn't the 3rd wire a ground connection? one was supposed to try it with that 3rd wire grounded vs not grounded and determine which had a lower noise floor, or sounded better.
I also owned the cable..the 3rd wire is a ground which hooks up on the amp side of things.
You may consider contacting David Weinhardt at Weinhardt Design in Bel Air, CA he is a featured seller on the 'gon....your cable was one of his favorites about a decade ago. Great guy, old friend...I'm sure he can advise you. Good luck.