This Little Giant Inner Cover provides extra ventilation, fresh air, and reduces condensation in your hive, whether in the field or backyard. It's the appropriate size for a 10-frame hive and the hole in the top correct size for use with the Little Giant Bee Escape which is sold separately, and provides an easy one-way route for bees when clearing the hive. Adds an extra measure of insulation and protection when placed under an outer cover. It also keeps the outer cover from sticking to the hive boxes, making it easier to remove without a tool or other supplies during harvest. This honey beehive box inner cover is made of 3/8" plywood with tongue and groove framing on both the cover and solid board. It can be used by any beekeeper, simply add the inner cover under the outer cover on the top of your hive to improve insulation. This is a great addition to a bee keeping starter kit or standard hive kit.