The entrance disc provides 3 different sized entrance holes. The first hole is for the entire colony to exit and enter the hive. The second position acts as a queen excluder to keep the queen and drones within the hive. The third position is to keep all the bees within the hive. The third position is great for closing up the hive if there is herbicide or pesticide spraying near the hive. The third position is also used for moving the hive and keeping the colony within the hive. This disc makes beekeeping FUN!