a few members ask me to buy the large exercise ball,sorry the propper name for it slipped my mind,i know that the ball is a good exercise unit but i know for a fact that in a gym like mine that has way over 100 peices of equipment,it is not needed,also for those who don't know how to use it,they will need some one to supervize them in my aerobics section and i don't have the additional staff at the moment,also the safety issue,there is no problem doing exercises with light weight on the ball but if some one tried to handle heavy weights then thats a completly diffrent story and he would be asking for trouble and risking injuries.so for those members who are looking forward to exercise on the ball,please buy your own and workout at your homes.