Acer Display 28" 60 Hz 4K UHD LCD Monitor | XB280HKBPRZ (Certified Refurbished) This Certified Refurbished product is certified factory refurbished, shows limited or no wear, and includes all original accessories plus a 90-day warranty. The 28" Twisted Nematic Film Display will leave you mesmerized The 16.7 Million colors makes colors much brighter A standard refresh rate of 60 Hz The 1 ms short response time eliminates "ghosting", for crisp and perfectly rendered action sequences.