I made this for my portable 16-inch screen so I can use it with my tablet holder to extend because it was for 10-inch tablets and it works great the base of the parts is 13mm if you are using a thinner screen or tablet use rubber on the bottom it will help as for the 2 holes on the top part it's for earth magnets because my screen has metal on the top side of it so I used magnets for stability use the magnet diameter is 10mm and the thickness is 2mm hop it help someone