“Cartridges don't last nearly as long as they used to, it seems like they're only putting half as much into them anymore, in fact some of the cartridges are completely empty when taken out of the box----21st Century needs to have better quality control over their product.
Also the cost is almost double of what they were a year or so ago, which looks like price gouging to me.”
“These filters have been a lifesaver for me. After being a smoker for 35 years, I didn't think I could do it. But these are so easy to use and work well.”
