The CPTZ Concealed Post Tie from Simpson Strong-Tie has a knife-like plate that is hidden in a saw kerf in the end of a post and secured with 1/2-inch-diameter galvanized pins. The tie keeps wood posts and columns 1 inch above the concrete, as required by code, reducing the risk of decay. It can be cast in place when the concrete is poured, or it can be secured with adhesives or mechanical anchors in a retrofit. The CPTZ is available in three sizes, for 4×4, 6×6, and 8×8 posts. Simpson Strong-Tie, 800.999.5099, strongtie.com