If you want to look for a monitor mount that can support Apple Thunderbolt 27" display, you need to consider two factors—weight capacity and VESA .
Shop displays and mounts that fit your Mac. Hold your Mac with stands and docks
Find great deals for Apple Thunderbolt Display 27 a 1407 Aluminum Stand Monitor Mount LCD No Screws. Shop with confidence on eBay!
VESA Mount Adapter for 24" iMac (Aluminum), 27" iMac (2009, 2010, 2011), LED Cinema Displays, Thunderbolt Displays Patented Replaces Apple VESA .
Buy Apple VESA Mount Adapter Kit for iMac and LED Cinema or Apple Thunderbolt Display (MD179ZM/A): Monitor Arms & Stands – Amazon.com ✓ FREE .