ContentRangeInstanceLength is an Int64 property that represents the size of an entity or the maximum number of bytes available in a "Content-Range" message header for a requested entity. 

ContentRangeInstanceLength is used with values in the ContentRangeStart and ContentRangeEnd properties to identify the requested byte ranges and upper limit. 

In the following example, ContentRangeInstanceLength is represented by the value 102400. 

  content-range: bytes 1-65536/102400
  content-range: bytes 1-65536/*

When the entity size is not know, is or insignificant, the value zero is used to represent the '*' in the following example: 

  content-range: bytes 1-65536/*

ContentRangeEnd 

ContentRangeStart