Product Details No more crawling under desks on your hands and knees! LUMI’s LDT20-C036UP Tripod Monitors Aluminum Slim Pole Held Mechanical Spring Monitor Arm comes with Top Fix fitting, which means this type of arm is perfect for limited space underside of the desktop. Providing 2 easily accessible 3.0 USB ports for charging and quality needed, its optimizing elbow spring gauge offers the performance and quality needed for weight adjustment. Quick-release VESA plate of exquisite structure and detachable joints make it an ideal support for longer life and easy installation. Product Features Installs from Top Side: installs entirely from above the desk surface Built-in Spring Tension Gauge: for perfect weight adjustments 2 easily accessible USB 3.0 ports Two Mounting Options: both desk clamp and grommet are included Smooth Arm Insertion: ensures easy installation Spring-Assisted Mechanism: allows to easily move up and down Quick-Release VESA Plate: for easy installation Specifications Product Category: Mechanical Spring Monitor Arm Rank: Premium Material: Aluminum, Plastic, Steel Surface Finish: Powder Coating Color: Matte Black Dimensions: 1416x176x649mm (55.7"x6.9"x25.6") Fit Screen Size: 17"-27" Fit Curved Monitor: Yes Screen Quantity: 3 Weight Capacity (per screen): 0~7kg (0lbs~15.4lbs) VESA Compatible: 75x75,100x100 Tilt Range: +90°~-90° Swivel Range: +90°~-90° Screen Rotation: +90°~-90° Arm Full Extension: 689mm (27.1") Pole Height: 562mm (22.1") Installation: Grommet, Clamp Suggested Desktop Thickness: Clamp：10~50mm Grommet：10~50mm (Clamp：0.39"~2" Grommet：0.39"~2") Quick Release VESA Plate: Yes USB Port: 2xUSB 3.0 Port Cable Management: Yes Accessory Kit Package: Normal/Ziplock Polybag,Compartment Polybag Instruction Manual Included: Yes