I bought these because of price, not durability. They clean well but fall apart and leak. This causes the vape to not work and/or medicine to go to waste. I have bought a 5 packs 3 times in one year and am down to two functional cartridges. And one I'm not sure one of them was made correctly. It has a missing piece when compared to the broken one that I just took out, but I don't have the special tools needed to swap parts and repair it.. I am about to buy another 5 pack, but that is only to hopefully find another vendor with a higher QA program.