This isn't a cartomizer product. This is a 3 piece ecig. There's wicking content but It isn't a stuffed cart. It takes advantage of a polyfill ring with regards to the thickness of a little nylon washer. it's possible about 2mm thick. The poly washer rests on a small flange https://electronic-cigarette31986.sasugawiki.com/6816707/jak_si_správně_vybrat_elektronickou_cigaretu_fundamentals_explained