Ear Piercing Shops What Does Ear Piercing With Cartridge Mean?

What does ear piercing with cartridge mean? - ear piercing shops

My sister goes to pierce the ears in a professional piercing shop, and they do not want the gun because she told me. But when she called the store, that is to use a cartridge, which is what we usually weapons, unless they put any weapons in the store. Mainly because the piercing with a needle?