KOKEN 1/2" Dr Attack Driver Knurled Handle - 6pcMade In Japan, Highest Quality, Most DependableSpecial heat treatment is applied on the bodyHardness of striking part is slightly softer to prevent cracksOn the other hand, cam part converts the striking power to twisted b y striking with a hammer, therefore this part is finished with higher hardness to improve anti wearStronger spring is adapted to convert the striking power efficiently to twisting power. Set Contains: 100P 32 Phillips Bits #2, #3,