The AUTOMATIC X4 Boost offers the user a choice between two modes of automatic brush agitation! The default setting is perfect for most flooring types, but more aggressive and deeper brush action can be activated by pressing the Boost Button located on the power head. This enables the spinning brush roller to attain greater resistance against the floor surface before height adjustments are made. For users who like automatic height adjustment , but still want a choice, the X4 Boost is the solution! This is the world's most technically advanced and uniquely easy to use vacuum cleaner! It features truly automatic height adjustment using and electronic controller that measures the resistance of the spinning brush roller against the floor surface to signal up or down adjustments, which ensures optimal performance on both carpets and hard floors. The user is also alerted to clogs, a worn brush, or a full bag and the vacuum automatically shuts off when brush obstructions occur to protect the motor and belts from damage. The AUTOMATIC X4 Boost has an instant use cleaning wand and suction hose, a lifetime belt warranty, tool free brush roller removal, a 40 foot power cord and three on board attachments. 90505AM