Ensure that your pet bees are happy, healthy, and hardworking when you protect them with the 4-pack Allied Precision Industries 3/8-Inch Plywood Beehive Insulation Inner Cover.This beehive cover provides extra ventilation and fresh air to your hive, as well as an extra layer of insulation and protection when placed under an outer cover. By adding this wooden vented Inner Cover to your 10-frame hive, it prevents your outer cover from being propolized and stuck to the hive body.