1. Standard: metric
2. Material: CR-MO steel
3. Surface treatment: blackening
4. Specification: 3/8 inch
5. Type T: T20, T25, T30, T40, T50, T55, T60
6. Type M: M5, M6, M7, M8, M10, M12, M14
7. H type: H4, H5, H6, H7, H8, H10, H12
8. Outer box size: about 15x9.5x5 cm
9. Overall weight: about 450g