The Schneider Electric A9GSB192 is an Acti9 SBI fuse-disconnector — a single-pole switch-disconnect for 22 x 58 mm fuse links, rated 125 A at 690 V AC per IEC EN 60947-3. That 690 V rating covers most 400 V three-phase line-to-line applications with headroom, and the 125 A continuous current handles motor branch circuits, feeder disconnects, or distribution sub-mains. The AM GG fuse curve means it accepts general-purpose (gG) and motor-protection (aM) fuse links, so you can match the interrupting rating to the downstream load without swapping the base.
Snaps onto 35 mm symmetrical DIN rail — standard for any European-style enclosure. At 35 mm wide (4 x 9 mm pitches), it occupies one modular slot, leaving room for adjacent breakers or contactors in a crowded panel. Depth is 70 mm, height 126.5 mm. Screw-clamp terminals accept 1.5 to 50 mm² rigid or 2.5 to 35 mm² flexible; torque to 4 N·m. Strip 12 mm. No padlock hasp on this variant — if lockout/tagout is required, specify the padlockable version.
The 125 A rated current is the maximum continuous current the fuse-disconnector can carry; the actual fuse link installed determines the overcurrent protection level. Storage temperature range of -40 to 80 °C and operating range of -20 to 60 °C cover most indoor panel conditions.