Because we cater to beekeeping in the South we only carry screen bottom boards. Our Screened Bottom Boards are fully assembled and made with galvanized mesh wire to allow ventilation. Perfect for temperature control during climate changes and provides assistant with pest management. The screen allows the mites to fall through and not climb back into the hive. The entrance allows space for a thin board for winter months or when treating for pests. The bottom board is a must for Florida and Southern beekeeping!