enable your bees to protect their hive easily as well as allowing you to control entrance and exit when you are needing to move the hive or do not wish the queen to have access. Also a way to keep out larger pests – these useful attachments screw on to your hive.
The entrance reducer (or mouseguard) allows the bees to control their entrance and assists them to keep out robbing bees and wasps as well as prohibiting mice free access to the cosy hive. Easily reversed to prevent the bees leaving the hive when you want to travel but still allows them ventilation.
The nucleus disc works in much the same way on a smaller scale.