Specification of triangular screwdriver: there are these: 1.8_, 2.0_, 2.3_, 2.6_, and so on.

Principle of triangular screwdriver: Triangular screwdriver is a special screwdriver. The manufacturer of the product doesn't want you to disassemble their products yourself, so use this special triangular screw. Of course, to use this triangular screw, you have to use it.