Here's a visual reference to get you started. The 510 cartridges shown above are commonly found in all markets and should work just fine with our Vessel Collection as long as they are less than 10.8mm in diameter for our Gen 1 line, and up to 11.5mm in diameter for our Gen 2 (every style with a designated '+'). They won't always look pretty - that comes down to your personal preference. Always feel welcome to ask your retailer for recommendations. We recommend certified/reputable brands that utilize the CCELL cartridge (TH2 or M6T Models) - they are proven, high quality and work exceptionally well with the Vessel Collection. WARNING: BEWARE OF COUNTERFEITS, THERE ARE MANY.
We put "Incompatible" in quotes for a reason. Technically they work with our line, however, you'll want to purchase a device from our Expedition, Craftsman, Formula, or Canyon series where the top section (the "Transition Module") is removable. The good news is because these cartridges are larger/wider and more rugged, they don't necessarily need the protection the Transition Module provides. For the more technically inclined, the Itsuwa manufacturer (Amigo Liberty line) and ones that are similar in design have a slight variation in thread pattern and the connection point also protrudes more than CCELL. These iterations may require a little pressure to "catch" thread with our line. Just be aware as you consider making a Vessel purchase.