Is the Extension Set for Tunze DOC Protein Skimmer 9005.400 needed?

[CyberGuy]

I am planning to get the Tunze DOC Protein Skimmer 9010 but on the ordering page it says that this skimmer need the Extension Set for Tunze DOC Protein Skimmer 9005.400 if used in the sump.

I am planning to use the skimmer in my sump.

Why is the extension needed for use in the in sump? Does it decrease the noise level? Does it decrease microbubbles?

Can I buy the 9010 without the extension kit?

 

[rvitko]

That piece is included, you only need the extension with a 9005. It sets up the skimmer to run in sump and handle water level fluctuations.