Adjustable post base, height adjustable post support, threaded deck support jack — this heavy-duty galvanized adjustable post support delivers precise height leveling and reliable structural support for all outdoor wooden post installations. Equipped with a full M20 threaded rod and dual locking nuts between two square mounting plates, this post leveling base allows easy height adjustment to compensate for uneven ground, sloped concrete and foundation discrepancies. Finished with hot-dip galvanized coating for superior rust and corrosion resistance, it is ideal for deck foundations, patio pergolas, privacy fences, garden gazebos, porch columns and shed support posts. Pre-drilled mounting holes on both top and bottom plates enable fast, secure installation on wood posts and concrete surfaces, delivering stable, long-lasting load-bearing performance for every outdoor structure.