Face material: Ag, AgNi, AgW, AgCdO, AgSnO2, AgZnO, AgC, AgSnOIn2O3 ,etc.
Middle material:  Cu, CuZn, CuSn, CuNiZn, CuBe, etc.
Base material :  Fe, Ni, CuNi, etc.
Specification :  As per customers requests