TWO MONITORS AT ONCE: Fits most 17''- 27'' Monitors with the load from 4.4 -19.8 lbs (2-9KG) for each monitor, VESA compliant patterns 75x75mm or 100x100mm; About the desk, we recommend wooden desktops with desk thickness within 0.59"-3.54".FULLY ADJUSTABLE RANGE: Your two screens will have 360° rotation, tilt angle +85° to -30°, swivel ±90° Upright up to 10"(260mm) and max extension is 20.8"(530mm). Both arms of the desk mount can be easily adjusted anyway you would like. No more bother rotating the angle by adjusting the screws.ERGONOMICS: Improve your overall well being by creating most comfortable viewing angle for work or gaming- Enjoy the freedom to adjust your monitor height and angle: Your spine, neck and shoulder will be thankful,Mounting your monitors can free up an extra 50% of desktop space and reduce clutter.DESK CLAMP OR GROMMET: You can choose one of two available ways of installation – C-Clamp or Grommet mount. The diameter of the hole in your desk must be 0.39-1.97 inch,Desk thickness must be within 3.54 inch, easy installation, Install In 10 Min or Less.Kindly noted: Pls DON'T adjust the tension screw without the monitor mounted on it , Adjust method: If the monitor keep rising up, Pls reduce the tension screw (to the direction of "-") On the contrary, Turn to "+", Many circles needed!