This feeder allows only the smaller birds (such as bluebirds) to access the mealworms through the 1.5" holes drilled into the sides. That leaves the larger birds (jays, mockingbirds, etc.) on the outside looking in! Roof lifts off easily for filling or cleaning. Comes with a hanging cable - can also be post-mounted. Dimensions: 11" W x 8.5" H (plus 6" hanger) x 7" D. By Enterprises of Garden Gate.