Hello and thank you for your interest in our Community.
I would like to confirm that our 10056-ST and 10056H-ST are both identical in terms of technical capabilities and standards used. The only difference would be the chipset ID it is meant to be compatible as. The 10056-ST is meant to work as an Extreme Networks 10056 SFP while our 10056H-ST is meant to work as an Extreme Networks 10056H SFP. If your switch is compatible with only one in particular, it would then be best to make sure to select the respective variant. Otherwise, if your switch is compatible with either models or with MSA compliant SFPs in general: then either of our modules would work fine and both provide the exact same service.
Hopefully this is helpful! If you have any further questions, please let me know.
Emmanuel B.