3.6 x 3.6" Post Base The post base is rust-proof, wear-resistant, and rock-solid with black powder paint, providing the standard inner diameter of 3.6 x 3.6 inches. The product fits deck brackets, porch railings, post holders, table leg, etc. key Features Strong & Solid The post base adopts powder-coated steel with a good performance in hardness and durability. Fits 4 x 4" Post The durable product provides an inner diameter of 3.6 x 3.6 inches. Its standard dimension allows you to install post 4 x 4 inches. Enhanced Durability There are four mounting holes on the bottom of the post anchor. Eight self-tapping screws need to be installed on the side of the post base. Easy Assembly It is convenient to operate according to the detailed instruction. You just need to use the included wrench to tighten the screws. Comprehensive Set The requisite accessories are equipped, including a wrench, expansion bolts, self-tapping screws. Universal Compatibility The post bracket is waterproof and sun-resistant with optimum material. It is very suitable for deck brackets, porch railings, stair handrails, mailbox posts, etc