From the product FAQ:
Modes. Gentle (40,000 RPM) for keyboards, electronics and delicate parts. Boost (80,000 RPM) for everyday dust on desks, vents and car interiors. Blowzer Mode (130,000 RPM) for heavier debris — sand, leaves, crumbs, workshop mess. Start low near anything fragile and step up only when you need to. Press and hold the power button to switch on or off, press it to change modes; press and hold the start button on the grip for instant full speed, and in Gentle or Boost click it to toggle the airflow.
Nozzles. Default for focused, all-round airflow; wide for a broader sweep; long for reach into deep gaps; flat for a blade of air along tracks, vents and seams; needle for pinpoint air in the tightest spots.
Sound. You will hear it — the motor's pitch rises with each mode. Gentle is the mode to use when quiet matters.
Which combination worked for you, on what? Reply with the job, the mode and the nozzle.