These WRBs include rainscreen or enhanced drainability functionality without the use of separate furring strips. A product that includes "air barrier" as a product type signals that it is fully adhered; it can then be considered a weather resistant barrier since it provides both bulk water AND air leakage control.
Some manufacturers state their non-adhered products meet referenced standards for airtightness as an installed product. Even so, we recommend as a best practice that the continuous rigid exterior sheathing layer be established as the primary air barrier layer for optimal airtightness and long-term performance. Products listed here that are not fully adhered could be paired with taped plywood or OSB sheathing seams to provide a very good foundation for comprehensive whole-building airtightness.