Do Mikrotik have some kind of approval/declaration letter that FCC ID: TV7RB912G-5HPND is valid for model RB912UAG-5HPnD-OUT.
I can´t get the usage certification here in Ecuador if the FCC ID if for one model and Basebox5 is another one.

Here the problem.
FCC ID: TV7RB912G-5HPND is for model RB912G-5HPND , not for model RB912UAG-5HPnD
neither RB912UAG-5HPnD-OUT.

https://apps.fcc.gov/oetcf/eas/reports/ ... 912G-5HPND


A

The conformance letter available from the product page (912UAG-5HPnD) says that the letter of conformity is for the product UAG and G. As the A just means it has a level 4 license so you can use it as an AP, and the U just means it has a USB port (and if you look at the image of the 912G board in the image - and in the certification testing) it has a USB port when being tested.

The boards themselves are printed with 912G 5HPnD so I suspect the slightly extended product code was chosen later to accurately add in the information about the USB Port and the L4 license. This would indicate that the FCC Code is issued for the device tested which may be labelled as 912G 5HPnD but is sold as 912UAG-5HPnD.

However the real answer is that you need a real answer from Mikrotik confirming this evidence is what I say it means and you are best to contact sales and support to get that officially in writing as none of us can speak for Mikrotik.

Regards
Alexander