Review on Builders Best 10151 Close Elbow: Optimize Airflow Efficiency in Tight Spaces by Jamie Behm

This is not so. This is aluminium. This means it's thinner and thinner than steel tubing (as any plumber knows). In some installations this may not matter. But if it's the part sticking out of the wall that the dryer connects to, it can easily expand and is useless for a good connection. In such a case, a short piece of steel tubing should be added to the open side to create a strong "nipple" for the connection.