I am not a big fan of the VANPEN battery pen, but their cartridges are excellent. Root Beer Kush is one of the best vape oils I have ever had. Vape smoke that feels thick in the lungs, but also seems to consume slower than other cartridges that have dense vapour. It is the closest to feeling like actual smoke that I've experienced with a vape oil. The flavour is very root beer like and potency is excellent. As said, I don't like their battery pen but the case this kit comes in is handy for carrying on the go. Highly recommended.