ALL 911s feature a fully automatic climate control system with integrated active carbon filter, the C4S getting the standard single-zone arrangement that is adjustable for temperatures between 18 and 30 degrees Celcius. Featuring a number of simple push buttons, including fully automatic and AC-off functions, the system is simple to use and provides 12 fan speed settings. Good ventilation is provided by a large windscreen vent plus four large, closable dash vents, while climate control is further assisted by green tinted heat insulating glass with graduated front screen tint. The power mirrors are heated, as is the rear screen.