Xceed Zip Compression Library Documentation
xcdCompressionLevel enumeration (Xceed Compression control)
Xceed Compression control reference > Xceed Compression control enumeration types > xcdCompressionLevel enumeration (Xceed Compression control)

xcdCompressionLevel
{
  xclNone = 0,
  xclLow = 1,
  xclMedium = 6,
  xclHigh = 9
}

This enumeration is used by the CompressionLevel property. Explanations on each parameter can be found in that property's help topic.