Bird S Pole Ground Anchor is for 1 in. diameter S Poles in this category only. Ground Anchor for mounting 1 inch outside diameter bird feeder S poles that slip onto its 3.5" slot and pin joint pole section. This ground Anchor can be screwed into the ground 18 inch for a stable platform. It has 1/2 inch turning holes to aide turning into the ground. The pole then slips onto the above ground anchor and its slots and pins secure it in place. Holds the pole sections above it 4.5 inches off ground.