Nuvo Iron Black 3.5″ x 3.5″ Post Cap (Nominal 4″ x 4″) Pyramid Ornamental Aluminium PCP02 for  3-1/2″x 3-1/2″ planed posts. 100% satisfaction. If you’re looking for fence or deck post caps, look no further. We got you covered with this Nuvo Iron Black 3.5″ x 3.5″ Post Cap (Nominal 4″