Allow purple martins to colonize in your yard with the Trio Purple Martin Pioneer House. This home was one of the first ever built from aluminum, which helps keep the martins cool during the hot summer months. Such construction also offers durability to your martin house and will last several seasons. Each of the 12 compartments is 6 inches long x 6 inches wide x 6 inches high, the perfect size for martins, and has a 2.125 inch entrance hole. Each compartment also has an individual lift up, snap out door so you can clean out one without disturbing the other nests. Guard rails along the porches of the home prevent babies from falling out of the nest and allow martins room to perch and preen. This is also accomplished with an included 22 inch roof perch. A set of 12 winter door stops close the house when your martins migrate south. The Pioneer home is compatible with any pole with a 1.25 inch outside diameter. Help purple martins nest in your yard with the Pioneer House. Assembly required. Made in the U.S.A.