Ties the masonry veneer to the substrate. The Concrete Seal Tie's screw portion has special alternating threads making it suitable for use with concrete, CMU, wood stud or brick backup, and is provided with EPDM sealing washers. Fabricated from Zamac zinc with a premium quality organic polymer coating, the 2-Seal™ Tie has a dual-diameter barrel with factory-installed EPDM washers to seal both the face of the insulation and the air / vapor barrier. This is an improvement over single barrel types which only seal at the insulation and render the vapor barrier susceptible to air and moisture infiltration if not precisely installed.