Returns or sets the unit label for the specified axis. Can be one of the following XlDisplayUnit constants: xlNone, xlHundreds, xlThousands, xlTenThousands, xlHundredThousands, xlMillions, xlTenMillions, xlHundredMillions, xlThousandMillions, xlMillionMillions, or xlCustom. If the value is xlCustom, the DisplayUnitCustom property returns or sets the value of the displayed units. Read/write XlDisplayUnit.
Remarks
Using unit labels when charting large values makes your tick mark labels easier to read. For example, if you label your value axis in units of hundreds, thousands, or millions, you can use smaller numeric values at the tick marks on the axis.