SZ-A11 is a front-mounting auxiliary contact block designed for use with Fuji Electric SH-4 and SH-5 industrial relays. It provides a 2NO (2 normally open) contact configuration that can be combined with the base relay to expand the total contact arrangement. The block is compatible with bifurcated contact relays and allows field modification without requiring relay replacement. When combined with SH-4 or SH-5 base relays, it enables flexible contact configurations such as 5NO+1NC, 4NO+2NC, or 3NO+3NC depending on the base relay configuration. This modular design provides cost-effective solutions for industrial control applications requiring customizable contact arrangements.