Product review (1 stars): Unacceptably Flimsy Material
For the price I was expecting something far more substantial.  The paper thin material of this coupler makes it very flimsy and delicate. This is not what you need when trying to create tight, strong joints in a system of ducts.  You can do as well by simply taping two sections together with aluminum tape.  If it wasn't so much hassle I would send it back.  I advise others to look elsewhere if they want a strong duct joint.