The GS2AD20 is an auxiliary contact support from the TeSys GS range, designed to mount on GS2 switch-disconnector fuse bases rated 32 to 400 A. It carries the NFC DIN UL fuse type — meaning it accepts the three common fuse form factors (NFC, DIN, and Class H/J) used across European and North American fused-disconnect panels. This is the part that gives you the early-break / late-make auxiliary contacts for status feedback or interlocking on the fused switch.
The switch rated current list — 32, 50, 60, 63, 100, 125, 160, 200, 250, 315, 400 A — covers the full GS2 base range. That doesn't mean the auxiliary contact itself carries that current; it means the support is mechanically and electrically compatible with any GS2 switch-disconnector in that ampacity band. The fuse type (NFC DIN UL) tells you the fuse clip geometry the base accepts: NFC (French standard), DIN (German), and UL Class H/J (North American). If your panel uses one of those fuse styles, this support fits.