The interrupting capacity is what decides where this breaker can be installed: 330 kA at 240 V, 242 kA at 415 V and 440 V, 187 kA at 500 V, and 3 kA at 690 V.
That is unusual for a thermal-magnetic breaker, but the ETU320 electronic trip does not rely on a bimetal, so the trip curve stays stable regardless of enclosure heat buildup.
Feature set — what is there and what is not
The ETU320 is a basic electronic trip — adjustable long-time and short-time pickup and delay, plus instantaneous. If the BOM calls for a communicating breaker with power metering or ground-fault alarm, this is not that part. If the spec just says '63 A MCCB, line protection, electronic trip', this fits exactly.
This is the standard catalog part, not an end-of-life or NRND variant.