Cutler-Hammer breaker on a T&B panel. Compatible?

Different brand breakers, but they look damn near identical. Does anyone know if this is okay?

Old Thomas and Betts panels were identical to Cutler and Westinghouse.
Haven’t seen T&B in 15 - 20 years.

Yep: Thomas and Betts T&B is an identical clone to Westinghouse/Bryant and Cutler Hammer. Watch out in wet areas for aluminum backpanels. Conneticutt Electric at one point continued making T&B breakers.

We need to know the panel type and wiring type to comment on “is this OK”.

If they are Eaton CL classified breakers, they probably are compatible, the Eaton BR is compatible with current and previous BR panels, and Challenger panels, only. Can’t say much about C-H but unless there is paperwork to prove compatibility with competitive equipment, it would only be good with BR panels & Challenger, even though T&B, was the old Challenger, line.

The whole UL listed, vs UL classified saga is clear as mud.