... screwdriver tip size .Top quality and wears wellTelecommunication Screwdriver tools Useage:1.T5 T6 T8 can disassemble desktop computer HDD ... can use for disassemble CD-ROM3.commonly used tools for disassemble mobile phone :"*"type screw use T3,T4,T5,T6,T7 ... model,T4 for some Motorola .T5 for Motorola and NOKIA ,T6 for all NOKIA mobile phone ,some samsung ,Motorola,Sony Ericsson .type screwdriver ...