This is the Park Tool SD-2 Phillips Screwdriver. The same professional tools your shop mechanic uses everyday will last you a lifetime in your home work station. This shop quality screwdriver is designed for comfort and durability. Featuring dual density grips and heat-treated tips and shafts. The #2 is a 1/4" shaft, perfect for derailleur adjustment screws. It is the most common cross tip ("Phillips") required.