Nikon D300 User Manual page 171

B
Selecting a White Balance Preset: the WB Button
At a setting of
PRE
([Preset manual]), presets can also be selected by
pressing the WB button and rotating the sub-command dial. The current
preset is displayed in the control panel while the WB button is pressed.
rIa
PRE
Control panel
WB button
Sub-command
dial
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