As far as I am concerned the SVD is the all around best portable vaporizer in the world. It is really too bad that e-cigarette type vaporizers are not being advertised for cannabis oil use. QWISO, RSO, BHO, quality concentrates like these, the cleaner the better, are awesome in this vaporizer when properly mixed with PG USP. I am going on 7 months now strictly using an oil vaporizer. I have been growing for 13 years, going on 14. I have smoked cannabis for over 30 years. By far, the best product I have tried in regards to portable vaporizing is a basic e-cannabis oil (quality concentrate diluted with PG USP). I use the innokin SVD. Nothing has compared. I have spent a ridiculous amount of money trying out different products, more than most can comprehend. Absolutely nothing even comes close to beating a basic innokin SVD with an iClear 30 or iClear 30b bottom fed unit. It takes any 18mm diameter battery. The unit can telescope to whatever battery length you choose between 350mm and 650mm. I just ordered my third SVD for $37. This will be an additional back up unit. I have seen units for well over $200 that don't even compare to the SVD. You can pretty much attach most other manufacturers devices to it. The SVD offers more options than any other oil vaporizer I have seen. As far as I am concerned, the SVD is the best. Many other company's products work better on the SVD because you can adjust the voltage and wattage. For example: I attached an Essential mini attachment to my SVD and I could get it to work far better on the SVD than the OEM's battery because I could fine tune the SVD to accommodate the attachment and my oil of choice. I must say, the SVD with the newly released iClear 30b feels heavy duty, almost like it is a medical tool or instrument. Very cool. I have only mentioned a small fraction of my experience with portable vaporizers and the SVD. I am healthier and happier since I began only vaporizing or ingesting concentrated cannabis oil. SVD with Essential attachment SVD with iClear 30b close up SVD with iClear30b Thank you - Have a very blessed day!