Free Shipping! Ergotron LX Dual Stacking Arm for Displays up to 24" (Black) Supports Two Displays up to 40", Supports up to 20 lb per Arm, 75 x 75 & 100 x 100mm Mount Patterns, For up to 2.6" Desk or Countertops, Provides up to 13" of Lift, Provides...