Inside, the W221's interior is also significantly different from the preceding model, even more dominated by leather, wood and metal. Where the W220 still had a fair amount of plastic fascias and switches, the W221 has replaced most of these by more luxurious materials such as wood, leather and metal. The interior features an instrument cluster with two large flat panel screens, one for the hard disk based COMAND system which includes the navigation screen and one replacing the analog speedometer by a graphical representation of it, which can display a range of additional information and can also be replaced by the Night View Assist display. Below the central COMAND screen are silver effect air vents, and a square, analog clock within the vents. Below the vents are metal tab switches with a black field behind them, to control the HVAC system (these functions are all also accessible via the COMAND system, which also offers access to some additional HVAC functions, such as foot-well temperature settings and air flow control).