Some assembly required

Half of the box spring at left.

The Wall Bed and Storage Units from Costco were waiting in the garage when Stan got to the project house in California Sunday. He went right to work.
He's followed assembly instructions from the Swedes okay, assembling countless bookshelves, dressers and tables, but this wall bed (Murphy Bed) is a new thing. . . and it is made by the Canadians with only the metal parts coming from China.
There's a bit more English in the instructions, millimeters and inches and plenty of pictures, and the product is a lot sturdier than the typical IKEA offering. But sturdier is heavier and the weight of this thing is onerous.
We finished the drawers and the framework, now comes the actual metal bed that is spring loaded. We'll take a break and go shopping.
First up, a queen sized mattress that can't be thicker than 12 inches or weigh less than 70 pounds. The box spring is built in. Will he be forced to buy a box spring anyway?