Allow purple martins to colonize in your yard with the Nature House 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 twelve 6"L x 6"W x 6"H compartments is the perfect size for martins and has a 2.125" diameter entrance hole. Each compartment also has an individual lift up/snap out door, so you can clean one out 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" roof perch. A set of twelve winter door stops close the home when your martins migrate south. The Pioneer House is compatible with any pole with a 1.25" outside diameter. Help purple martins nest in your yard with the Purple Martin Pioneer House. Assembly required. Made in the USA.