Sold as 1 Each. Screen Sizes: 17' - 32'. Weight capacity: 4.4 to 17.6 lbs. for each arm. C-Clamp and Grommet base options included. 2 x USB 3.0 ports for easy connection of your devices. Tilt: 90 degrees up / 90 degrees down. Easy to install. All hardware for installation and instructions provided. 11.5 Inches of Height Adjustment. Swivel: 360 degrees at two joints and 180 degrees at one joint. Fits all Samsung, LG, ACER, ASUS, HP, DELL, VIEWSONIC, SONY and other branded monitors with VESA 75 and VESA 100 mounting patterns. VESA 75x75 and 100x100 compatible. Rotate: 360 degree (between landscape and portrait modes). Supported by manufacturer's limited lifetime warranty.