Features and Benefits: Extra deep 3/4" socket; Use with a 1/2" drive or 7/8 hex; Can be used with an impact wrench; Extra deep 3/4" in. socket loosens the cage bolt to unlock air brakes on trucks. Also removes the air brake booster for replacement. Use with a 1/2" in. drive or 7/8" in. hex. Can be used with an impact wrench