Unfortunately, no pix of the guts. Nothing special though. The boxes are made of folded up aluminum flashing material. On the inside is a simple Pi attenuator, grounded to a lug under each BNC connector. The inside of the step attenuator looks something like VK2TIL's... lots of foil shields and solder. Somehow, it never occurred to me to put it on the network analyzer. I'll do that at some point. That thing was a bit of work, even for its lack of beauty...not sure I'd bother with all that again.