Specification: With most WALI desk monitor mount with 1. 375??? (3. 5cm) diameter center pole. (Pole NOT included). Fits one monitor up to 27???, Support weight up to 22lbs, and VESA 75x75mm to 100x100mm. Max extension: 28 inches. Compatibility Model List: M001, M002, M003, M004, MF001, MF002, MF003, M001XL, M002XL, M001LP, M00LP, MLP01, GSDM001, GSDM002. Design: The high-grade arms extend and retract, tilt to change reading angles, and rotate from landscape to portrait mode. Arm 3-Tier length: Tier 1:10", Mid-Tier: 8", Tier 3: 10". Dynamic: Monitor arm is easily adjustable, allowing to work in a more comfortable, and ergonomically correct position to reduce neck and eye strain. Package Includes: WALI Single Fully Adjustable 3 Tier Arm x 1, Mounting Hardware Kit, VESA Plate x 1, experienced and friendly US based customer support available to assist 7 days a week.