1、Plastics 
High quality engineering plastics, such as ABS, PC and PP, which are characterized by high heatproof performance, high toughness and high anti-corrosion

2、Copper parts
Optimum design; tight jointing between plug and sleeve; strong elasticity; easily inserting and pulling; preventing safety risk brought by electric arc due to bad contact. High quality phosphor bronze prevents oxidation and copper rust, and provide good conductivity and long service life.