Frame Designation and Function
The 'TMF' designation points to a thermal-magnetic release mechanism, but in this variant the release is configured for switching duty rather than full breaker-level protection.
Current Production and Sourcing
Sourcing is straightforward: the part is quoted to order against your BOM quantity.
The 125 A frame footprint is shared across the XT1 family, so busbar kits and terminal shrouds from the same series fit without modification.