Triple Defense System: Our 19-inch squirrel guard for bird feeder pole combines 3 layers of protection: (1) Smooth, rotating PC surface blocks climbing, (2) Stainless steel spring causes instant wobbling (up to 60° swing) to destabilize jumping squirrels, (3) 19-inch diameter and serrated design edges to stop squirrels in their tracks All-Weather Durability: Crafted from high quality PC material , this squirrel baffle for shepherd’s hook withstands sun, rain, and snow without fading, rusting or cracking. The rust-proof metal buckles and spring ensure years of reliable use, saving your bird feeders season after season