For a complete secure sealed installation, you must use Calimortar in between the chimney manifold and the chimney anchor plate.
1st Step: Place the anchor plate above your pizza oven chimney manifold and mark the 4 holes with a pen.
2nd Step: Drill the 4 holes on the pizza oven manifold using the exact size drill bit recommended by Tapcon, which in many cases it is already included in the anchors package you'll buy.
3rd Step: Clean all the concrete dust from the holes you drilled and from the top of the pizza oven chimney manifold.
4th Step: Apply a 1/8" - 1/4" layer of Calimortar above the area of the chimney manifold and place the 6" anchor plate in place and tighten all the 4 concrete anchors.