From the Physic Pro kit description:
With this kit, you can continue your study of statics and dynamics from previous lessons and begin your study of more advanced topics in physics, including fluid dynamics, energy, oscillation, hydraulics, and pneumatics.
By adding advanced topics like fluid dynamics to your physics repertoire, you can now build some really spectacular models and devices, such as a wind tunnel, pneumatic shocks, and a hydraulic lift. You will see how physics extends far beyond the classroom, giving us an amazing set of tools that can be applied in the real world to engineer marvelous things.
Here's a link to the original Thames & Kosmos Physics Workshop and here is link to the more advanced Thames & Kosmos Physics Pro set shown above.