Jewellery designed specifically for body piercing is special because the materials can be worn in new or healed body piercings long term, safely and comfortably. This means you can keep the same post or back in your piercing and just swap the front part which we commonly refer to as tops.
You should consider either Threadless or Threaded type body jewellery. Threadless posts and tops push together and pull apart; threaded ones have the top screw into the post.
If you already have threaded or threadless posts from us, all tops of the same type (sold separately) here will be compatable. Body jewellery like nipple bars and navel curves can also be either type but are sold as one whole piece.