They use pods. There are various ways to refill a vape pen or an e-cigarette. When copyright initially arrived onto the marketplace, they designed the “pod system” mainstream. See Introducing the Geek Bar Pulse Disposable, a compact but large-efficiency disposable vape device effective at delivering as many as 9000 puffs, https://vaporizeraussie.com/product/copyright-2-pods-x-8-packs/