When the rubber sheet pulled down. The volume of air in a plastic cap increase. The internal air pressure air moving from the DL so that d with low pressure from the outside into the body. Make the balloons.Camo out
When pulled the sheet down Increasing the volume of air in the plastic. Pressure within the air down. The moving air from a low pressure from outside the body. Making balloon inflated
When you pull the rubber sheet down, the volume of air in the plastic cover is increased. The pressure within the air down. The air is moving from the low pressure from outside into the body. The balloons.Swell out.