I designed a similar construction, but in the form of a box about four foot high with opening sections both sides. One opens to reveal the occupant's bent bottom emerging from a padded hole, with the insides of the door sections offering a selection of dildoes, lubricants, paddles, canes etc. The other opens to give access to her head, with a couple of handles just below connected to clamps on her nipples inside the box, allowing the user to twist the handles to encourage her to greater efforts or just to enjoy the sensation of her trying to scream with her mouth full.

I reckoned that this model, positioned somewhere like the lobby of a suitable club, could operate on a simple slot-machine system, thus saving the expense of full time attendants.