1. The shell frame is of high grade (18 modulus 80A). high breaking capacity (10kA), and strong adaptability of accessories. 2. The wiring column has the advantage of higher safety. 3. Current-limiting contact system, magnetic blown arc extinguishing device, avoid products and equipment to withstand large short-circuit current, improve product arc extinguishing Ability to ensure the improvement of breaking capacity. 4. The shell and function keys are made of imported PA nylon with high flame retardant, high temperature resistance and impact resistance. 5. lts shape is novel, its structure is reasonable, and it has many patent protection.