the Eureka Forbes Quick Clean DX vacuum cleaner has a knob behind the dust bag that serves as a control for adjusting the suction power of the vacuum cleaner. This knob allows you to regulate the airflow and suction strength according to the type of surface you are cleaning or the level of dirt you need to tackle.
By adjusting the knob, you can increase the suction power for more stubborn debris or decrease it for delicate surfaces to prevent damage. It provides you with greater control and flexibility while using the vacuum cleaner on various surfaces and cleaning tasks. However, it's essential to consult the user manual of your specific model for the most accurate and up-to-date information about its features and functions.