Precision screws were named by the Japan Photographic Machinery Association’s collective standards, and the correct name is “cross-recessed machine screws for precision equipment”. The cross drive hole is #0, which is smaller than #1, and the standard sizes are determined as No. 1 type, No. 0 type 2, and No. 0 types 3. The standard screw size is M1.0 to M2.6. As for its uses, it is used for cameras, as mentioned in the future, and for glasses and precision instruments. Precision drivers are necessary for tightening during use.