Description Used to provide ventilation to the hive. The screened bottom board features a sliding solid bottom that allows the beekeeper to control the amount of ventilation without having to disturb the hive. Consists of a 45 deg slanted front landing board with the bottom board and solid constructed sides, along with a heavy-gauge galvanized steel mesh screened center and a solid sliding bottom for long-term use.Dimensions:22.5 in L x 16.44 in W x 2 in H