This 27-piece assortment contains the famous Chapman midget ratchet, screwdriver handle, extension, 1-1/4 Inch square drive adapter with a standard assortment of adapters, plus (11) Allen Metric Hex Adapters Packaged in the traditional brilliant yellow crush resistant, blow molded, polyethylene case. - Chapman Ratchet Screwdriver Set, Number of Pieces: 27, Includes: (1) Chapman Midget Ratchet, (1) Extension, (1) Screw Driver Handle, (11) Allen Hex-Type Adapters - Size Indicates Distance Across Flats 0.05 Inch, 0.0937 Inch, 0.1406 Inch, 0.2187 Inch, 0.0625 Inch, 0.1093 Inch, 0.1562 Inch, 0.25 Inch, 0.0781 Inch, 0.25 Inch, 0.1875 Inch, (3) Slotted Head Adapters - Size Indicates Width of Blade 0.1875 Inch, 0.25 Inch, 0.375 Inch, (7) Metric Allen Hex Adapters - Size Indicates Distance Across Flats 1.5 mm, 2 mm, 2.5 mm, 3 mm, 4 mm, 5 mm, 6 mm. Includes: (1) Chapman Midget Ratchet, (1) Extension, (1) Screw Driver Handle, (11) Allen Hex-Type Adapters - Size Indicates Distance Across Flats 0.05 Inch, 0.0937 Inch, 0.1406 Inch, 0.2187 Inch, 0.0625 Inch, 0.1093 Inch, 0.1562 Inch, 0.25 Inch, 0.0781 Inch, 0.25 Inch, 0.1875 Inch, (3) Slotted Head Adapters - Size Indicates Width of Blade 0.1875 Inch, 0.25 Inch, 0.375 Inch, (7) Metric Allen Hex Adapters - Size Indicates Distance Across Flats 1.5 mm, 2 mm, 2.5 mm, 3 mm, 4 mm, 5 mm, 6 mm