That's the workhorse trip unit for general distribution and motor branch protection where you don't need electronic adjustability. At 240 V AC it's rated for 187 kA; at 415 V AC it's 121 kA; at 440 V AC it's 75.6 kA; at 500 V and 690 V AC it holds at 7.5 kA. Power loss is 25 W maximum, which matters for enclosure heat rise in a packed panel.
Temperature derating — the real ampacity on your panel
This breaker is listed at 100 A from 40 °C up through 50 °C. At 55 °C it drops to 98 A; at 60 °C it's 96 A; at 65 °C it's 94 A; at 70 °C it's 91 A. That's a shallow derating curve — you lose only 9 A over a 30 °C rise above 40 °C.
The breaker measures 130 mm high, 76.2 mm wide (3 inches), and 70 mm deep. Depth of 70 mm means it clears most shallow backpan enclosures without a sub-panel extension.