Military question (branch of service, POland 1920-30)

I am wondering what branch of service or any other information anyone might be able to provide from the pictures I am posting (Grandfather, sometime in the late 1920's early 1930's).

Thanks!

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  Opa.jpg
  
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  Opa2.jpg
  

I tried to do a little research, they look like ulans/mounted soldiers but am not sure. You need to ask in the military forum, Identyfikacja section, where guys drop in with identification cases:

odkrywca.pl/jaki-to-pulk-kawalerii-,660830.html

Thank you very much for your help and your quick reply. I will post on the other website as well, hopefully there are some english speakers there, too.

You should be lucky aim, those are regimental numbers on their shoulder straps,should be easy to trace from there :)