I wanted to fix my Sonoff Ns Panel Pro to the wall but I didn't have any free electrical boxes. I created this plate to house both the Sonoff Panel and the Google Nest Thermostat. It is fixed through the holes in the 503 box. The nest is fixed with the m2 x 12 screws. to the Brass Insert Knurled Nut on the back and the sonoff panel is fixed equally but with m3 x 12 screws, to complete the support there are 2 covers for the screws so as to make everything perfectly smooth.