This item is for reconciling the position of the throttle trigger (in throttle zone) and the actual ESC throttle output. The default is linear and we can change it to non-linear via adjusting the throttle curve. For example, if adjust it to +EXP, then the throttle output at the early stage will be higher (than the output when the curve is linear); if adjust it to –EXP, then the throttle output at the early stage will be lower (than the output when the curve is linear) and very smooth.