Between Copper and Aluminium
Copper Tin or Silver Plated
Plastic , Nickel Plated Brass, Stainless Steel
DIN 95363/A , DIN 95363/B, DIN 95363/C
DIN 42548
DIN 42553
DIN 42551 A / EN 50216-4 3 size NW22/ NW31/ NW40