It's rated 30 A at 40 °C ambient, with interrupting capacity of 65 kA at 120 V AC, 25 kA at 277 V AC, and 14 kA at 347 V AC.
The 65 kA at 120 V AC is the headline number — that's the SCCR the breaker can clear without welding or venting. At 277 V (common for lighting panels) it still holds 25 kA, and at 347 V (Canadian 347/600 V systems) it's 14 kA. For a 1-pole device these are solid figures; you can coordinate downstream branch breakers with reasonable confidence if the available fault current is known.
Derate to 29 A at 45 °C, 28 A at 55 °C, 27 A at 65 °C, and 26 A at 70 °C.
Width is 25.4 mm (1 inch) — one pole, one module width on a standard DIN rail. Depth is 75.1 mm, height 129.4 mm. It's a straight thermal-magnetic breaker for basic branch protection.
