Most cartridges can be refilled with the possess THC oil, CBD vape oil or e-liquid prior to deciding to will need to remove them. If it’s a 510 design cartridge, just unscrew the mouthpiece and fill the tank up. You may have to make use of a syringe for accuracy. https://andycvlym.activosblog.com/31773081/detailed-notes-on-thc-cartridges