Your Philips Sonicare toothbrush comes with three different intensity settings: low, medium and high. When attached, the brush head will automatically select the recommended intensity. To manually change the intensity, you can simply turn ON the handle and press the mode/intensity button. Note: Your brush heads must have BrushSync technology capability for the intensity setting to be selected automatically when attached. The following toothbrush head models have BrushSync technology: C3 Premium Plaque Control, G3 Premium Gum Care, W3 Premium White, W DiamondClean.