It's this one. It was an excellent monitor, when I tested it and I'd have kept it had I not had the Asus 4K 144Hz monitor, which actually has one or two important advantages over it.
The one thing I was quite disappointed about was the sound. The BenQ product page makes a big deal about it, but it was somewhat tinny and certainly had no bass unlike what they claimed. If it had lived up to the hype, I might have just kept it as a luxury purchase for this unique feature.
It's currently going for £700 and is likely to drop further over time, I believe.