there are too many kinds screwdriver set in the market,and some with many size bits,but some size you don't have to use them ,maybe never,so it will be better to know which size would be the right one you are searching.
here we summarize some regular size,and will update in completely.
>P2: For the bottom screw of iPhone,and other small screws like Huawei P10,P9 .
> P5: For Macbook Air and pro.
>Y 0.6: For the inside screw of iPhone7.
>SL1.5:For precision screws like glasses.
>SL1.7: For iPhone;
>T1,T2,T3,T4: For most smartphones from China like Huawei;
>T6:For some laptops;
>H2.5: For iPhone 6s;
>U type : For power outlets reparie.
> PH00/PH1: Used for most of the smart phone's repairing.
>PH2: Remove bottom screws of the laptop and some toys too.