We reported about this model a couple of times before and it looks like it just now started listing. ACER in is now listing the XB321HK in an Ultra HD flavor combined with NVIDIA G-SYNC display technology for reducing screen tearing or display lag.
This new IPS LED-backlight monitor supports a native resolution of 3840 x 2160 pixels, that's 138 pixels per inch. The monitor a 32” IPS panel which suggests an AUO Optronics AHVA (Advanced Hyper Viewing Angle) panel similar to that seen on the BL3201PT/PH.
The panel offers a 1000:1 static contrast ratio (normal), 350 cd/m2 brightness, 4ms (GTG) response time and 172/178 degree viewing angles. The Predator is equipped with built-in stereo speakers and has 1x HDMI, 1x DisplayPort 1.2 and 4-port USB 3.0 hub. Acer is claiming 100% sRGB coverage and accuracy. The stand appears to attach using 100 x 100mm VESA so you should be able to remove it and use an alternative VESA 100 mounting solution if desired.
Acer’s MSRP on the Predator XB321HK is a whopping $1299.