That 500 A holds flat through 50 °C — only starts to derate above 55 °C, hitting 495 A at 55 °C and 480 A at 70 °C. For a panel builder, that means you can run this breaker at full nameplate in a warm enclosure without worrying about nuisance tripping, as long as ambient stays under 55 °C. Breaking capacity is the headline number here: 330 kA at 240 V, 242 kA at 415 V, and 242 kA at 440 V. The ETU310M overcurrent release gives you adjustable short-circuit pickup (li) from 1 500 A to 7 500 A, plus protection function I (instantaneous only). No ground-fault monitoring, no phase-failure detection, no communication module — this is a straightforward thermal-magnetic-style electronic trip unit for motor or feeder protection where you don't need the bells and whistles.
Footprint is 138 mm wide by 248 mm tall by 110 mm deep. That 138 mm width (5.4 inches) is a standard MCCB form factor — it'll drop into most existing panel cutouts sized for a 3-pole 500 A frame without re-drilling. Depth of 110 mm leaves room behind the door for wiring gutters or a backplate. Power loss is 99 W maximum at full load.