Yes, the wires enter the box 'through' the top of the SLB.
What also might not be obvious is that the left-hand box is rotated for a reason; the reason is to allow connection of the second pipe - which is located behind the pipe from the SLB. The two boxes are connected with a rigid nipple. It is not possible for the boxes to move relative to each other; the nipple is corroded fast in place.
#111545 - 12/31/0610:32 AMRe: My Favourite Assembly
Mike, here's a view of the other side of that unit.
The "hose" is a piece of sealtite that starts at the first "bell" box (see the 90 fitting on the end?), passes through a gap under the duct, attaches to a vertical piece of pipe (not visible), then returns to sealtite ... seen in this pic flying through the air, with but an unusual assortment of fittings in the middle!
Here's a closer look:
#111548 - 12/31/0604:12 PMRe: My Favourite Assembly