What does the suffix B and IS mean on a 250SV43BIS transformer?

Issue:
Forms B and IS on a buck boost transformer

Product Line:
Dry Type 600V and Below transformers

Environment:
Applies to Low Voltage Transformers by SquareD/Schneider Electric

Resolution:
The suffix B designation is 80 degree C rise.
The suffix IS designates an Electrostatic Shield.

Released for: Schneider Electric USA