I recently posted a question about an evic supreme and wanted to say thanks to those that responded, the responses were very helpful! I recently purchased a vapor flask dna 40. Although I am relatively new to vaping about 1 year this device is very inconsistent compared to others I own. This is to say the least a disappointment. Using two kanger sub tanks one with .5 ohm coil one with kanger ooc nickel coil. Some times the device recognizes a switch between the two sometimes not. When it does not recognize the switch to occ nickel the vape is alarmingly hot!! When it does recognize (set at 450/20watts) the vape is really good, if I put ti down for 5 minutes or more the vape is cold and non existent. If I loosen the tank reattach it will recognize and give a few great vapes. then back to non existent, does well with the rta. My question is are they a company that stands behind the product, will they help me resolve these issues? Has anyone had problems and had them rectified? If so was it relatively easy or a long drawn out tedious process?