This Teng Tools TORX keys with T handles, each have a short arm and a long arm. The short arm allows excellent leverage allowing easy tightening and loosening and also has a slot to work on tamperproof screws. The long arm allows access to more difficult to reach areas. The keys are made from Chrome Molybdenum alloy steel for extra strength. This 7 piece set of TORX keys for internal TX heads consists of the following sizes 3 x 100mm TX/TPX keys (TX/TPX10, TX/TPX15 and TX/TPX20). 3 x 150mm TX/TPX keys (TX/TPX25, TX/TPX27 and TX/TPX30). 1 x 190mm TX/TPX key (TX/TPX40). Supplied in handy storage tray.