Compatible with Echo Show 15(1st, 2nd gen) and Show 21. The bracket is designed for the Show 15.6" Smart Display and is suitable for installation under cabinets with a wood thickness range of 16-24mm Height adjustment. Use thumb screws to control the tightness of the screw, making it easy for the X plate to slide up and down on the pole to adjust the height of the Show 15. The height adjustment range is 1-8cm Two mounting options. Method 1 is you need to drill holes, using machine screws and hex nuts to install. Method 2 is No need to drill holes, use the self-tap screws. Method 1 installation is recommended for greater stability, using machine screws and hex nuts to install the bracket Multi-Motion. This under cabinet mount can rotate horizontally and vertically, tilt up and down, swivel left and right, and move forward and backward, allowing you to view the screen from any angle Saving-space. Take your device off the counter or wall and place it under the cabinet. This saves more space on the counter and allows for closer screen viewing Mounting Space Required. Please pay attention to the height measurements and ensure that the under-cabinet has enough space to mount the bracket and Show 15 device.