Do I need a boost mobile sim card or a sprint one?

Hi, I recently bought a used sprint iPhone and plan on switching it to boost when it arrives. I've already made sure it had a clean esn/ imei and all that good stuff Lol. I just wanted to know once they switch it over am I supposed to use a sprint sim card with it or a boostmobile sim card?

You need to use a Boost SIM card.

You could get Sprint, it is better than Boost and get the best protection by installing Leo Privacy Guard. It will make your device totally secure.