6 airflow holes strategically placed are what make Vessel the best cartridge battery. When you consider the location in the Vessel battery right under the threading on which the cartridge connects, you will see a series of air holes all around it. Yocan UNI Pro also shields the cartridge http://cbdgummies1000mgnw.blue-blogs.com/1938038/details-fiction-and-and-the-entourage-effect