The front of a rackmount sound module, or the top for tabletop units, typically contains a small screen or panel to provide information to the user (e.g., an electric piano sound may be called EP 1). This may be an LCD panel (which may or may not be backlit) or an LED alphanumeric display. This may be supplemented with LED indicators to show the status of various features. In some models, LED indicators are embedded within a translucent button, so pressing the button shows its status on the button. There is usually a volume control, some types of buttons or knobs for selecting sounds and changing settings, and a power button. The smallest, simplest piano modules may have only a volume knob and a knob to scroll through several piano sounds. The most complex synth modules may have a large number of knobs, buttons, and faders to control oscillators, filters, and amplitude settings.