Tiny Tuesday - Air

When I first saw the title for this challenge I thought how do you encapsulate such an essential invisible element of life in a small format. Certainly pointing uo to the skies would not fill the bill. Eventually I got round to thinking about the different ways we use air and came up with the pressure in our tyres which I suppose makes our journeys smooth and bearable. So my digital air pump for the car became the subject of my blip