The portholes look about 6in wide and surrounded by a plastic disc.

But you are more likely to find this plastic disc hurtling towards the grass at a park than drifting spookily through space.

The matron hands me a red plastic disc with the number seven stamped on it.

A team has to throw the plastic disc from one end of a pitch to the other without the opposition intercepting.

Buttons are propelled using a flat circular plastic disc of approximately the same diameter as the buttons.