Part 4175 currently is 28 LDU in depth, the BI version is 30 LDU. I don't think the part has changed dimensions over the years so it seems to be incorrect from back when it was originally made way back in 1998 - 2008. I guess it was assumed to be 28 LDU since that would be the expected dimensions normally.
I've attached the latest BI version of the part.
I've attached the latest BI version of the part.