Squirrel Stopper Pole System, Bronze Objective Lens Diameter_50mm Using a secondary attractant is Using a secondary attractant is critical to the performance of your Mosquito Magnet® trap The absence of perches will help deter large perching birds such as Grackles and Doves from using the feeder Squirrel Stopper™ includes: Decorative cardinal top or finial top Top holder 2 1" outside diameter cross tubes 4 eyebolts and nuts for hanging feeders 3 3' x 2" outside diameter tube sections with "twist and lock" attachments Squirrel Stopper™ shroud (factory attached to middle tube section) Steel Auger This pole system is 100% squirrel proof