The North Face's DryVent waterproofing system is a superior, waterproof, breathable technology utilizing a polyurethane (PU) coating that consists of a tri-component mutli-layer formula for waterproof protection, moisture permeability and durability. This technology has been lab tested in The North Face Quality Assurance lab to ensure the best possible durability and function while also maintaining a comfortable level of breathability. The minimum level of breathability achieved using DryVent is: 600 g/m²/24 hours on the Moisture Vapor Transfer Rate scale.