Review on CTA Tools 2066: The Ultimate Heavy-Duty Oxygen Sensor Socket for Professional Mechanics by Boss Spangler

A narrower groove provides more contact. The extra ring around the center eliminates the flex found on cheaper tools. Like other reviewers, we struggled using a locally purchased tool to just round the corners of the sensor's hexagon. The CTA tool immediately caught and bit. The O2 sensor unscrews in seconds without slipping. Have used (and broken) several sensor connectors over the years and this has had none of these issues. I doubt I'll ever have trouble with an O2 sensor again. Worth every dollar.