For the ultimate versatility for sealing every rough opening, ZIP System liquid flash is a fluid-applied flashing membrane made of STPE (silyl-terminated-polyether) technology. This high-performance formulation combines the durability of silicones with the toughness of urethanes. Bonds to wood, concrete, masonry, architectural metals, glass, PVC, FRP, EPDM and most other building materials. Weather-resistant and tack-free in as quick as 20-40 minutes, depending on conditions. Target thickness achieved when substrate is no longer visible.