Comments about Gary Metal 14CSC 14" Crimped Start Collar 105114:
This collar is made of heavier gauge steel, and is well made. I was impressed compared to collars purchased at my local HVAC supply house.
Unfortunately, I could not use this collar as I needed it to transition from 1.5" duct board. The tabs are so small, it would even be difficult to use with 3/4" duct board.
For sheet metal ducts, would work great.