The ABB XT4SU3100AFF000XXX is a 2-pole molded case switch from the XT4S 250 TMF series, rated at 15 A and designed for wall mounting. It serves as a manual disconnect and isolation point in power distribution — think of it as the service-entrance switch for a sub-panel or a machine disconnect that needs a visible break and lockout capability.
Wall-mount design means it bolts directly to a backplate or enclosure wall — no DIN-rail adapter needed. Plan for gland-plate entry below the switch; the cable exit path is straight down. The 2-pole footprint keeps panel fill factor manageable for a sub-feed disconnect.