The speed bump ahead sign and post kit comes with a cast iron base, post, sign, and attachment hardware, so you won’t have to buy anything separately. The 17” diameter base alone weighs 31 lbs and thus, is sturdy enough to withstand even strong winds. The post has predrilled holes like the sign and comes in two parts, which measure 4’ in height and 1.625” in diameter upon assembling. The 3M engineer grade reflective sign is made of 80 mil thick aluminum and resist weathering and rusting.