Felted Overshirt

It measures the ability to dissipate water vapor and body heat. The system grades performance: a Grade 1 provides basic breathability, appropriate for protective materials for normal urban use, while a Grade 5 ensures maximum vapor escape during intense exertion, achievable, for example, with high-performance membranes (e.g., >20,000g/m²) or special active fabrics.

It analyzes the specific weight and packability of the garment. Grading defines practicality of transport and packability: a Grade 1 is generally assigned to outerwear that emphasizes weight and structure, while a Grade 5 indicates maximum agility, typical (but not exclusive) of "Ultralight" garments, designed with minimalist designs and easily foldable materials.

It indicates the level of body temperature maintenance and thermal insulation. The scale rates the intensity of protection: a Grade 1 indicates light insulation, often characterized by the absence of padding or thin linings, while a Grade 5 certifies extreme warmth, which can be provided by materials such as goose down with 800+ Fill Power or ultra-high-weight synthetic insulation.