PERM-A-BARRIER® VPL 50RS UV STABLE Membrane is a fluid applied, one component, STPE (Silyl Terminated Polyether) vapor permeable air and water barrier. When applied to approved construction surfaces, PERM-A-BARRIER® VPL 50RS UV STABLE is designed to cure and form a resilient, monolithic, fully bonded elastomeric membrane, and to create a continuous barrier against air infiltration and exfiltration, reducing associated energy loss and condensation problems. PERM-A-BARRIER® VPL 50RS UV STABLE Membrane is specifically designed to provide superior protection against the damaging effects of air and liquid water ingress on the building envelope. Vapor permeability allows the wall to breathe and dry, minimizing the risk of water vapor from being trapped and condensing within the wall. While PERM-A-BARRIER® VPL 50RS UV STABLE Membrane is vapor permeable, it is impermeable to liquid water, allowing the material to act as a water drainage plane within the wall.