I wanted to drop by and say thanks to the folks at IBTanked for the last 14 months of low-fuss vaping. This particular 22mm XL tank (5ml) has been in action every single day for the past 11 months. I vape DIY unflavored only so one tank gets a lot of use from me. I punch my own non-flanged Smok single coil XL cartos using a Siam Mods V2 carto punch. Even with four medium holes punched in each carto I am still using the first set of O-rings that came with the tank.