CPTZ Concealed Post Tie - The CPTZ concealed post base provides a clean, concealed look while providing a 1 standoff height above concrete. The 1 standoff reduces the potential for decay at the post end and satisfies code requirements for posts that are exposed to weather, water splash or in basements.. The CPTZ is installed with 1/2 in. diameter galvanized pins (supplied). Knife plate, washers and standoff base are ZMAX-galvanized steel. The standoff base has an additional textured, flat black powder coat finish for aesthetic purposes. The 1/2 diameter drift dowels are mechanically galvanized in accordance with ASTM B695, class 55.