Extension kit for the Ergotron LX Pro monitor arm that allows configuring multiple monitors (dual/stacked and extended multi-monitor arrangements). Connects to an existing LX Pro arm to add an extra arm/adapter for two monitors placed side-by-side or stacked. Compatible with VESA 75x75 and 100x100. Made of aluminum, black color, with built-in cable management and Ergotron Constant Force technology for smooth height/position adjustment. Desk clamp requirements: approximately 10–60 mm thickness.