That TM240 designation means the thermal pickup is fixed at 80 A and the magnetic short-circuit trip is adjustable — you set the instantaneous trip threshold to match the inrush of your load, typically a motor or transformer feeder. Breaking capacity is the headline here: 121 kA at 240 V, 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at 690 V. Three poles, so it switches all three phases.
Derating and thermal reality
Above that it steps down: 76.8 A at 55 °C, 75.2 A at 60 °C, 73.6 A at 65 °C, and 72 A at 70 °C.
The 76.2 mm width (three-pole) is standard for a 160 A frame SENTRON; it occupies one 3-pole mounting position on the DIN rail or bolted bus. Mechanical endurance is rated at 15,000 cycles. That's the number of on-off operations the mechanism is designed for before wear-out. For a line-protection breaker that sees maybe a few operations a year, that's effectively lifetime. For a breaker used as a disconnect that cycles daily, track it.