Often referred to as an Under siege railing system, from the film staring Steven Seagal.
A railing system is used to move object around a room or building. The system usually consist of 2 rails one upper and one lower, with a set of wheels attached to a harness which an object can be placed.
Normally a seat and straps is used instead of an object in which a person can sit. The seat usually contain one or several holes in which a penis or object can be can be inserted, whilst a person is sat on the seat. A person will often sit in the seat and another will move them around the room inserting objects in to the holes contained within the seat.
"Andrew build a large railing system in man shed."
"Andrew enjoys being monkeyed whilst sitting in his railing system"