Teng TEN510504 T-Handle Hexagon Driver 4mm This Teng Tools Hex key with T handle has a short arm and a long arm. The short arm allows excellent leverage allowing easy tightening and loosening. The long arm of the Hex key has a ball point head which allows a working angle of up to 30 degrees and therefore improves access. Manufactured from chrome vanadium steel for toughness and durability. The TEN510504 T Handle Hex Driver has the following specifcations: Size: 4.0mm. Short arm length: 12mm. Long arm length: 100mm.