It carries a rated current of 50 A at 40 °C and holds that rating through 50 °C before starting to derate: 49 A at 55 °C, 48 A at 60 °C, 46 A at 65 °C, and 45 A at 70 °C. That thermal curve means an enclosure with marginal airflow at 55 °C still gets 49 A of continuous duty. Breaking capacity is 52.5 kA at 240 V, 32 kA at 415 V, 13.6 kA at 440 V, and 7.5 kA at both 500 V and 690 V. Rated insulation voltage is 800 V, so the breaker can be used on 480/277 V and 600/347 V systems with margin.
The 101.6 mm width (4 inches) is the standard 4-pole MCCB footprint for this class — it occupies four 25 mm (1-inch) module spaces on a DIN rail or mounting plate. Depth of 70 mm means it clears most standard enclosure gland plates and backpanels without interference. Maximum power loss is 14.6 W. In a sealed enclosure with multiple breakers ganged together, that heat adds up — account for it in the thermal budget.
If your panel ambient is higher than 40 °C, use the derated values: at 60 °C you lose 2 A (48 A), at 70 °C you lose 5 A (45 A). At 690 V the same breaker still interrupts 7.5 kA, which covers most motor branch circuits at that voltage level. Shunt trip (STL) for remote tripping.