Compatibility for Thomas & Betts breakers
This handy chart seems to show that the Eaton CL230 breaker is a "Classified" replacement for the Thomas Betts TB230 breaker.

Since this is a pretty common breaker sold at national big box home improvement stores it should be straightforward to compare the two.  These cheaper breakers are normally not even in a package, making comparison even easier.

The comment from isherwood about the type of panel you have is valid.  This is meant to point you in the right direction, but its not a definitive "certified" answer.