15-Feet telescoping pole fits all heath purple martin houses of wood . Heavy duty, rust-resistant galvanized steel pole. Pole diameter: bottom 1-1/2-inch middle 1-3/4-inch top 1-1/2-inch. Pole can be easily raised or lowered using the Heath keylock system. Innovative design locks pole into place for desired height. Built to stand the test of time. Heath's galvanized steel martin house poles have graced America's yards for years, even decades. With superior rust-resistance throughout seasons of use, you can be sure to house your martin's year after year.