This box is fantastic. I installed this on the inside of the garage to house the satellite dish receiver, its power supply and the AC outlet for power. It also houses the transformer for the router. I did not used it in the NEMA configuration where the hinges are at the top. The hinges are on the side. I didn't care to paint it, cause it's in the garage.

The product listing is not clear. Currently the 12x12 is available with or without a backplate, the model with the backplate is the more expensive model.

For my project, the smaller 8" unit would have been a better option, I didn't even notice that option when I ordered. So, I have a lot of empty space in mine. And I could have saved about 10 bucks. Oh well.

I wanted non metalic because I am putting Z-wave wireless equipment in it.

It is outdoor NEMA 3R rated. But, personally, given the built-in holes, I wouldn't use it outdoors. Though people indicate using it outdoors after covering the holes. I am using it indoors for an alarm panel box.

A good project box. I purchased the 12X12X4 box. The dimensions are outside dimensions with the sides being 1/8 inch thick so 1/4 inch less on the inside. The hinge makes the box larger outside as mentioned in other reviews with the outside lid dimensions being 12.5X13. I purchased the one without the stand off tray but it appears to be the same box, just without the extra piece of plastic, and has four stand off posts inside in each corner. There are also two mounting holes in each of the corners which have raised lips around them so the inside rear of the box is not completely flat. The posts and raised lips could be in the way if you need a flat mounting surface and plan to use all the space in the corners although they could be ground down.
The door has a slight overlap on the outside of the box of about 1/2 inch so the outside space on the three sides without the hinge is about 3.5 inches. This limits anything being mounted through the side walls in that area that would protrude unless you cut the door overlap. Hinge side wall is about 2.5 inches before it steps back the extra 1/2 inch for the hinge.

Great project box for Raspberry Pi. It has plenty of room for power supplies and relays.

Great price on these awesome enclosures, these are priced quite a bit lower than the big name hardware stores. I am using them in a backup Solar panel/battery setup I use one for the charge controller and the other for switches and meters.
They are weather resistant, meaning if you spray them with the garden hose, you may have a problem, they are, as stated, non-metallic so the potential for shorts is greatly decreased. I bought two of them and couldn't be happier with the purchase, I will buy more of this same item as need dictates.
Let me know if you found my review "Helpful" or if you have any questions.
Thanks!