I have been using purple ducks for years and I decided to try these as a cheaper option.
1. It doesn't filter nicotine well and the taste is bitter.
2. To open the package, you need about half an hour because the plastic wrap is so tight that you need a wheel. Similarly, the drawer doesn't open at all because it is wedged due to poor construction.
3. Don't buy it! It's a complete disappointment, a waste of money

Basically, they have a plastic cartridge inside instead of a filter. Also, at the edge, you screw on a plastic accessory to hold the cigarette, and there are only 2 of them in the package. So, if you accidentally throw away the entire cartridge after use without removing it, the remaining cartridges will be useless. I prefer the small transparent ones that are only for tar, they do the same job and maybe even better