Steel framed bench
The basis of the bench is a sturdy 'box steel' frame. On top of which is an adjustable wooden shelf- which can be bolted in one of two positions (front or centre). The bolts are held in place by easily removeable wing nuts. All of the horizontal parts of the frame are covered in protective foam (not to protect the bench), the front and back sections are fixed, the sides are removeable. The restraint is provided by 6 galvanised steel eye bolts, 4 of which have split links attached . In this prototype, all body contact surfaces have been covered with 0.63mm black latex, in addition a sturdy 'waist' belt has been fitted. The bench can be used both front to back and side to side and either faceup or down- very versatile, and it can be flat packed (nearly).
Split links were chosen because single triggers broke in use and split links are shorter than double triggers. Split links are very strong and easy to open or close. The other advantage is the fact they are quite short, which further helps to limit movement.
The shelf is held in position by galvanised steel bolts making sure that it is secure.This picture also shows the waist band and 'inspection' light. There were wheels on the bench, ideal for moving around, but we found that static was a lot better. 
As we had some latex left over from the bed it was thought a good idea to cover parts of the bench- such a nice feel. Some of the covering was not done very well- but we learn!