Metric System in Canada

Metric air is not to be confused with Medic air. Oxygen in your body is measured by 0 2 saturation as a percentage. Metric air is measured in a pressure gradient inside a closed container, which in this case is a tire. You may not know it but the vapor pressure for Oxygen is different than the vapor pressure for nitrogen. Some will try to sell you Metric nitrogen rather than metric air. Be aware metric air is already 77% nitrogen. Be careful, do not pay for all the nitrogen, you already have mostly nitrogen in your tires. Just buy what you actually need.