Price reduction: Was £13.95!
This toy has a serious scientific purpose because it provides a stunning demonstration of vortex formation and transmission.
When the toy is 'pumped' a doughnut shaped ring of air (the vortex) is generated and moves outwards at high speed.
It has sufficient energy to create a noticeable impact at some distance - hence the toy interest.
Ideal as a design project to attempt to recreate the same effect using cardboard boxes, etc.