Defrost hose question...

So if I understand Redfish and 416, the hoses are both 2" diameter and flare or expand to 2 1/2" at the dash vent end?

Here's an outfit that sells duct hose by the foot, including a 2" to 2 1/2" reducer.

http://www.nostalgicairparts.com/ac/duct-hose-vents-4.html