Product review (1 stars): Unfortunately, the Sunbean 6589 is no longer manufactured.
I ordered these to go in my Sunbeam Model 701 Ultrasonic Humidifier and found out that they no longer make the 6589 Demineralization Cartridge. Instead, the Kaz DC-51 Demineralization Cartridge is being substituted, but it's about 1/2" thicker than the original 6589. This meant that it would not fit properly in my Sunbeam 701, preventing the water tank from seating properly. I suspect that some other Sunbeam ultrasonic humidifiers will have the same problem, because they are constructed similarly.

A very poor job of coordinating specifications for a replacement part for a discontinued item in my opinion.