Not breathable
Not much water vapour/sweat can pass through this garment.
Moderate breathability
Breathable enough for moderate activity, such as walking in cooler temperatures.
Extreme breathability
Large amounts of moisture can pass through the fabric for a prolonged period of time. Suitable for high aerobic physical activity.
Low
Uninsulated. Ideally suited to warmer conditions and/or high aerobic activity.
Medium
Some insulation. Suitable for a wide range of conditions.
High
Designed to provide warmth and protection in even the coldest months of the year.

