Bit 0 - 1: Contrast (0=Low / 1 = Medium / 2=high)

Bit 2 - 3: Speech volume (0=Low / 1 = Medium / 2 = High)

Bit 4 – 5: Buzzer volume (0=Low / 1 = Medium / 2 = High)

Bit 6: Entry/exit indication

[Flags]
public enum RKP
{
    Contrast0 = 1,              // bit 0
    Contrast1 = 2,              // bit 1
    SpeechVolume2 = 4,          // bit 2
    SpeechVolume3 = 8,          // bit 3
    BuzzerVolume4 = 16,         // bit 4
    BuzzerVolume5 = 32,         // bit 5
    EntryExitIndication = 64,   // bit 6
}

[Flags]
public enum RKP
{
    LowContrast = 0,
    MediumContrast = 1,         // bit 0
    HighContrast = 2,           // bit 1

    LowSpeechVolume = 0,
    MediumSpeechVolume = 4,     // bit 2
    HighSpeechVolume = 8,       // bit 3

    LowBuzzerVolume = 0,
    MediumBuzzerVolume = 16,    // bit 4
    HighBuzzerVolume = 32,      // bit 5

    ExitIndication = 0,
    EntryIndication = 64,       // bit 6
}

contrastComboBox.ItemsSource = new[] { RKP.LowContrast, RKP.MediumContrast, RKP.HighContrast };
contrastComboBox.SelectedItem = currentValue & (RKP.MediumContrast | RKP.HighContrast);
//and so on for each combo box...

//and when you want the result:
RKP combinedFlag = (RKP)contrastComboBox.SelectedItem | //other combo box items