Ergotech Freedom Arm FDM-MAC-G01 Metal Gray LCD Compatibility: 27 Thunderbolt Display, 24 and 27 LED Cinema Display, 24 iMac (Aluminum), 27 iMac Product Includes: plate (for iMac), 27.6 aluminum articulating arm, desk clamp base Offers 14 of dynamic one-touch height adjustment Full extension range of 26.7 Capacity: 20-30.8lbs