Pine Slatted Rack For 10 Frame Hive (assembled)Fits just beneath the lowest hive body and above the bottom board. It has the same outside dimensions as the brood box and is 2 1/4 inches deep. The frames in your brood box line up with the slats so Varroa mites will fall through the screen in your bottom boardBecause a slatted rack moves the bottom of the brood chamber further from the entrance, the queen tends to lay eggs all the way to the bottom of the frames, thus extending the brood pattern.In the winter, a slatted rack keeps the brood chamber warmer so that the queen can lay eggs all the way to the bottom of the lowest frames.In spring and summer when the colony populations are the largest, a slatted rack provides ventilation and extra cluster space by allowing the queen to lay eggs lower.Tends to reduce swarming.Can be left on the hive all year longThe picture represents the materials used to assemble the slatted rack and not the specific item you will received.Pine is the most popular wood for beehives. All of my woodenware is made to exacting specifications in my state-of-the-art workshop.