Rio Beach XCB202CB-01 Sand Anchor, Nylon & FiberglassThe secret to the best umbrella sand anchor is the flat, circular blade. When this is screwed into the sand it will hold it's grip and keep the umbrella upright. Other sand anchors simply will not hold up in even moderate winds. Support beach umbrellas with a pole diameter of up to 1. 25 inches Rust proof Test to withstand winds up to 30 MPH Nylon & fiberglass construction.