Okay weird. I was expecting these tanks to be those 'stationary swimming' type things where you'd then hold on to a little propeller thing (I don't know technical terms for this ****):
If it's not a setup like that, how does it work?
![endless_cover.jpg](https://crownspas.com/wp-content/uploads/2017/12/endless_cover.jpg)
![51Ig7KNziVL._AC_SX466_.jpg](https://images-na.ssl-images-amazon.com/images/I/51Ig7KNziVL._AC_SX466_.jpg)
If it's not a setup like that, how does it work?