6 Duckbill Earth Anchor 20" Long 6 Pack - Duckbill Earth Anchor 40-DB1 Installing Duckbill Earth Anchors using an upward pull rotates the Duckbill into a load-lock position approximately 15 from horizontal. Further tension causes the anchor to plane sideways through undisturbed soil, increasing its holding power to up to 300 lbs. Nothing of the anchor is above the ground. Made of aluminum alloy, it will not corrode.