... alloy contact material** Alum. Frame: fire retardant, no electric shock, never fades color** Phosphor Bronze: high resilience, antioxidant ... , good electric conductivity** Brass: good electric conductivity2. Rating: 250V, 10A3. 1 to ... procedure. There are lifespan test, insulation resistance test, electric strength test, heat test , etc.Qulity is ...