Four poles, rated 50 A at 40 °C, with a breaking capacity of 75.6 kA at 240 V AC — that's the short-circuit current it can safely interrupt without welding contacts or venting plasma into the enclosure. At 415 V it still holds 52.5 kA, and at 690 V it's 7.5 kA, so the voltage you're protecting determines the fault-clearing margin. The UVR means the breaker drops if control voltage falls below the dropout threshold, which is common in safety circuits or emergency-stop chains where a loss of control power should open the main feed.
Ratings that matter for panel fit
Dimensions: 130 mm tall, 101.6 mm wide, 70 mm deep. That's a 4-pole MCCB that fits a standard 100 mm-wide DIN-rail slot — the width is the critical number for multi-breaker rows. Thermal derating is published: it holds 50 A from 40 °C up to 50 °C, then drops to 49 A at 55 °C, 48 A at 60 °C, 46 A at 65 °C, and 45 A at 70 °C.