“Your manufacturer continues to produce defective, unusable cartridges and have done so for more than 9 months for 1.6% & 2.0% regular cartridges. You asked me to send back (7 cases)...so you Cam replace with defective ones. No thanks.”
“The filters I finally receive are good however the email communication of arrival time is horrible because you have to be home to sign for them and with very low communication through emails it's very annoying when the private delivery people will show up.”
“I've been using 21st Century for many years now and am very happy with the quality of the products I receive. The buy 9 plus one free is a great deal for the money.”
