What the frame and trip tell you
The XT2L 125 TMF 70-700 3P F F UL/CSA: The 125A frame means the breaker's mechanical and thermal design is rated for continuous current up to 125 A — the trip unit plugged into it sets the actual overload and short-circuit protection point. The TMF 70-700 designation means the thermal (overload) element is fixed at 70 A and the magnetic (short-circuit) element is fixed at 700 A. That's a non-adjustable trip curve: the breaker trips on overload at 70 A and on instantaneous short-circuit at 700 A. No dials, no interchangeable rating plugs — what you order is what protects the circuit. This suits fixed-load applications where the protection setting won't change over the life of the installation.