Depending on the capabilities of your radio, up to four sliders are shown on the Tuner window. The Slider Override settings can be used to set the maximum level for each slider, or disable one or more completely. The settings above indicate that the AF Gain can be set to a maximum of 21% and the Pwr output can be set to 12 watts maximum.
Set a slider to 0 to disable it. Set the slider to 100 to provide the full range.