Product Description Use this 27" Surface Mount Post with a Base Plate (not included) for securely mounting any Mail Boss mailbox on a 4"-8" sidewalk or curb (above the road surface). This 27" heavy-duty steel post is made of 10-gauge and 14-gauge galvanized steel with a durable powder-coated finish. From the Manufacturer Use this 27" Surface Mount Post with a Base Plate (not included) for securely mounting any Mail Boss mailbox on a 4"-8" sidewalk or curb (above the road surface). This 27" heavy-duty steel post is made of 10-gauge and 14-gauge galvanized steel with a durable powder-coated finish.