Product review (4 stars): Does not fit into a standard vent pipe through the wall
If you are using this from the machine to turn a close corner behind the dryer  it might work fine. But I am using a periscope vent behind the dryer, and this elbow to fit over the end of that and turn the corner into the standard aluminum pipe that goes through the wall. But the crimped end of this elbow is the exact same diameter as my standard through the wall duct so It doesn't fit into it. Only by snipping every 1/4 inch all the way around could I scrunch it small enough to insert it into the pipe out of the house.  It does turn the corner pe gectly, in less space than a regular elbow, so I made it work using tape.