1. Material: chrome molybdenum steel 2. Weight: about 600g/set 3. Size: about 142x105x38mm/set 4. Purpose: nut screw screw extractor 5. Process: heat treatment 6. Features: the material is firm and not easy to deform, good toughness, high hardness, easy to use, time-saving and labor-saving operation, complete specifications, wide applicability, wear-resistant and anti-rust 7. Contains: 10 sleeves (9/10/11/12/13/14/15/16/17/19mm); 1 long rod (7x90mm)