Thank you! I didn't get the use of the word cartomizer or the difference between cartridge and cartomizer. Knowing what the number is helps too.
If it contains the heating element and the juice in the same one piece unit, it's a cartomizer. Companies call them "cartridges" because it's more intuitive for new people. A cartridge contains only juice. Some pre-filled cartomizers are refillable. Most are not. Companies make their money by selling you cartomizers because no other cartomizer will fit. You become dependent on them for replacements and refills if you use an e-cig that doesn't take a standard 510 or other standardized, refillable cartomizer.