Features: Strong impact available: Place the screwdriver at -25 for 2 hours take it out for 3 minutes to prevent the impact of heavy objects and the insulation layer will not be damaged. Pull test: Prevent 168 hours at a constant temperature of 70 . After taking it out and placing it for one minute conduct the test with a tensile force of 500 N for three minutes and the insulation layer will not fall off. Material: The tong head is forged from professional alloy tool steel (s55c-1) which increases the service life by 30% compared with other raw materials. The hardness of the cutting edge after special high-frequency heat treatment reaches HRC58-62. The induction hardened cutting edge can cut soft and hard wires. Multiple sizes and specifications: This screwdriver set has multiple sizes and complete specifications which can meet a variety of work needs. Strong magnetic head: The head of the screwdriver is equipped with strong magnetic which can easily absorb metal small parts such as screws. Specifications: Material: Steel alloy Function: Screwdriver includes: 1 *6pcs Insulated Screwdriver Set