Upgraded MaterialThe screwdriver bits are made of S2 tool steel, which is more durable than CR-V steel. HRC: 58-62, reduce bit head wear/ deformation. Improved Working DepthCompared to the old 115 in 1 screwdriver set, the working depth of the new bits 135 in 1 screwdriver increased by 30%. Even screws hidden in deep places can be removed more easily. Upgraded Accessories108 precision screwdriver bits and 20 accessories specially apply for disassembling mobile phone. This screwdriver set also contains special bits (EX #6 - #10 and Dr #6 - #10), it is specifically applied to remove rusty/broken screws but should be used with the slow electric drill. Portable DesignCompact size makes it very convenient to carry. The integrated design prevents the screwdriver from scattering or falling off during transportation. Multiple Application ScenariosThis screwdriver set can be used to repair electronics and home appliances such as mobile phone, laptop, glasses, watch, camera, television, air conditioner, refrigerator, etc.