Mass Flow Resistance (MFR)Mass Flow Resistance (MFR) is our index on measuring wind permeability and breathability. Over the past 30 years, 100% windproof outer shells have become the industry norm despite limitations in breathability and the clammy feel it produces for the wearer. Letting air and wind flow through the garment makes it more comfortable to wear and also effectively transports moisture away from the body.
We work with MFR to measure how windproof a garment is, where MFR8 is close to 100% windproof but stills lets you stay dry and MFR2 means optimal breathability with limited wind protection. To measure the MFR value, air is drawn through the fabric using an adjustable vacuum, until a pressure difference of 100 Pascal is achieved; then the flow is measured. The pressure difference is divided by the flow to provide the resistance i.e. the MFR value.
Keeps you dry in light precipitation and is windproof enough for all weather types. The wind permeability transports moisture effectively away from the body compared to a fully windproof garment. Example product: Einride Jacket
Ideal for more intense activities where moisture-wicking and breathability are important but you still need to be shielded from wind. Example product: Gere.
Ideal for high-intensity activity where breathability is more important than wind resistance. Example product: Mithril Kevlar.