Big Foot provides a broad foot for range or prism poles when elevations are more critical than horizontal accuracy. The 2 1/4" domed foot supports the pole in soft soil, sand and mud by preventing the point from sinking in. The rounded bottom allows for easy plumbing and balancing. It can also be used under water. It fits most poles with male 5/8-11 threads. Big Foot weighs 5 oz. and is made of Derlin a very tough and dense plastic. NO more rusting.