One of the accessories available for the Monster 821 is the Ducati Quick Shift up/down, an electronic system derived from racing that makes it possible to change gears without the use of the clutch and without closing the throttle when shifting up, and shifting down without using the clutch, but only with a closed throttle. The system consists of a bi-directional microswitch integrated into the gearchange lever linkage that, when used, sends a signal to the engine control unit. The system acts differently depending on the direction of the change, integrating advance ignition and injection during the upshift phase, and controlled throttle opening (automatic ""blipping"") when the gear pedal is pressed in downshift mode. The magnitude and duration of the solutions are implemented in such a way as to ensure maximum fluidity in various riding conditions. In acceleration, the DQS system saves fractions of a second that would otherwise be lost by closing the accelerator and acting on the clutch lever, and increases stability because the time in which there is no power output is reduced. When downshifting during braking, DQS allows the gears to be easily engaged without having to use the clutch, letting the rider concentrate exclusively on braking and cornering manoeuvres. This system not only makes sport riding more enjoyable, but also represents a valuable help in city traffic and winding roads that require frequent gear changes.