I don't really know for sure, but I would think it would be the dihydrate form. AFAIK most salts don't naturally like to exist in the anhydrous form if they can exist in the hydrated form, and (once again, AFAIK) the dihydrate form of CaCl2 is the only hydrated form of that salt.
like I said, not 100% sure on that, but fairly confident.
Also, I just googled that product, and it looks EXACTLY like the CaCl2 that I have (obviously, CaCl2 dihydrate)