Black Mountain Products 2000lbs Static Strength Exercise Stability Ball with Pump, 65cm Blue

I use this balance ball as an office chair... I realised I can't go all day on just one type of chair... I need to switch to something alse after a few hours, otherwise my legs would start getting uncomfortable... so, I start the work day with the balance ball, and after a few hours, when I feel I'm getting tired of that position, I transition to the chair... The pump is pretty flimsy, but I think of the pump as more of a bonus and don't consider it in the overall quality and value of the item. The ball itself is made of a nice thick material and it holds air well... I decided to go with the 85cm size (the biggest there is) because I can make it short or tallest, by just regulating the air in it...