MaxUrl in Request Filtering vs. UrlScan

IIS has UrlScan tool and inbuilt Request Filtering module(IIS 7 and above).  The default configuration came with product are as below.

Default values for [RequestLimits] section in Urlscan.ini :

 MaxAllowedContentLength=30000000

MaxUrl=260 - the maximum length of the request URL, not including the query string

MaxQueryString=2048

Default values for Request Limits in Request Filtering module: 

Maximum allowed content length (Bytes) = 30000000

Maximum URL length (Bytes) = 4096

Maximum query string length (Bytes) = 2048

Why there is a huge difference  for maximum URL length/MaxUrl default values while other two properties are in sync ?

Thanks!