tablet/ phone holder for 15 mm square tube (kitchen lamp accessory)

This is the model for a tablet mount for my kitchen/ desk/ workbench lamp extension arms (see my profile or search for this printables number: 589283)

I built mine with a length of 250 mm square tube for a 10 inch tablet (15x15 mm tube like it is used in my extension arms). The mounting tab can be slid on the lower tube of the extension arm and is movable back to front.

What else do you need:

• 2x M4 nuts
• 1x M4x20 bolt
• 1x M4x8 bolt