[Cable] How likely to purchase non Stac 02.50 Dcm476.

I am buying a Thompson Dcm476 from Canada Computers (in St.Catherines) for use with TekSavvy. I went to the store and the guy did not know the firmware and the site does not say anything either. My friend bought one from their and he says it works no problem. My question is, how likely is it that the modem is not Stac 02.50. Does the firmware appear on the box.