This Screen Bottom Board includes an air tight metal tray and is fully Assembled. We recommend painting the surfaces exposed to the weather with an exterior grade latex paint. Screened Bottom Boards make it easy to monitor varroa levels in your hive. Mites fall through the screen onto the metal tray. After 24 hours count the number of mites to help determine if mite treatments are needed. Available in 8 frame sizes only. Our "New" style hive stand is designed to be used with this screened bottom board. Comes with wooden entrance reducer.