This is a special, multi-purpose, two piece weathervane rod used to mount a weathervane in a variety of manners. 18" Steel Weathervane Assembly Rod. Compatible with most Good Directions weathervanes. Used to replace current assembly rod or for use with weathervane figures. Can also be used to adapt cottage and garden size weathervanes for cupola installation. The base is a 3/4" with a 11/32" top.