Product review (3 stars): Great for straight vents. Not great for turns.
Works well for straight vents. My vent has two 90-degree turns. Two different sections of the tool sheared in half due to the friction against the vent elbows. Also the instructions include duct taping each section together. This seems like a poor design if the instructions include duct tape our product together. If your vent is a straight shot, this tool is awesome.