The new Chest Expander Exercise is a mix of different exercises, but still it is special and new!
Because you can do the Propeller in front and behind your body. The front and back version is nothing new, the big difference to other Expander Exercises is that the chest expander is pulled apart all the time, so you have tension during the whole exercise!
But have a look:
The Propeller increases shoulder mobility noticeably. Beside the difficulty to control the circle motion your grip will be tested!
Last but not least, these exercises will develop much tension/strength within your upper body and they are difficult to do. But you as an athlete will notice the improvements you will make!