This innovative tool can be used much like any other 1/4 hex bit driver, but its true usefulness is in the ingenious "breakaway" articulating shaft. The driver bit holder, which is seated in the magnetized driver socket for in-line use, is flexible at the joint to allow for operation up to 12° off-line, useful when normal operation is impossible because of restricted access due to an adjacent surface or fixture (walls, door frames, plumbing, or studs). The revolving shaft has an exterior aluminum sleeve to hold onto for added stability. 1/4" hex shaft. Taiwan. Very, very handy for every shop.