Mi Air Purifier - Maintenance the Sensor

The Black Sponge
Some batch of air purifier comes with a black sponge inside the sensor cover, some asked whether the sponge needs to be removed.

Xiaomi had explained that the black sponge is to protect the purifier sensors, in order to block the dust from sticking to the sensor, you do not need to remove it.

Of course, do not panic if you do not have sponge inside your sensor cover, as Xiaomi's support team had explained, different batches are using different protection method, if no sponges found with your sensor, do not worry.