Could have been a viable product [SEP] Bad design. The pictures in the posting show or imply that the glass vial threads screw into the top inhaler brass colored  section. It does not, it just holds by supposedly a friction tight fit, so not only is it a loose physical fit, it also allows your oil or scent to leak out and/or dry up prematurely. This is the only problem I have with these inhalers, and it's a major one. They got sent back. On the search for some quality ones that actually properly seal-in the vapors.