The Schneider A9K23216 is a 2-pole miniature circuit-breaker from the Acti9 iK60N series, rated 16 A at 30 °C with a B tripping curve. For a distribution board in a commercial or light-industrial setting, that's the standard you need.
At 36 mm wide (4 module pitches of 9 mm), it takes up two pole widths in the enclosure, so you can plan your fill factor around that. Depth is 78.5 mm; height is 85 mm. That leaves enough clearance behind a standard 120 mm deep enclosure door.
