The parts have to be small and light for 10,800 to fit in one cardboard box, capable of being lifted by one person.
Probably less than 70 lbs, or averaging one tenth of an ounce per part.
Imagine if it was just generic springs, suitable for any number of applications? A “box o’ springs” sounds a lot less intimidating, doesn’t it?
In past, enthusiastic police have discovered “bomb making materials” like spooled copper wire, duct tape, road flares, roofing nails, a can of gasoline for a lawnmower, and household cleaners in someone’s home and vehicles. Which obviously means they were going to make bombs with them.