1.If you choose"1.5mm", it means that the package only include 1 piece 1.5mm screwdriver, it's not means 4 pieces!
2.If you choose"2.0mm", it means that the package only include 1 piece 2.0mm screwdriver, it's not means 4 pieces!
3.If you choose"2.5mm", it means that the package only include 1 piece 2.5mm screwdriver, it's not means 4 pieces!
4.If you choose"3.0mm", it means that the package only include 1 piece 3.0mm screwdriver, it's not means 4 pieces!
5.If you choose"4pcs", it means that the package include (1.5mm+2.0mm+2.5mm+3.0mm) screwdriver, in total 4 pieces!