BUNN 39000.1010  has been discontinued by the manufacturer. updated to Scale Pro cartridge new number 56000.0033  SYSTEM, WEQ-SCALE-PRO.X (system with head old and new are not interchangeable) 

Bunn WEQ 56000.0033 Single Water Filtration System with Lime Scale Inhibitor - 10 GPM

The Bunn Scale-Pro filter cartridge has a flow rating of 6 gpm (gallons per minute), and its maximum pressure is 125 psi. To ensure your coffee brewer, espresso machine, or tea maker is always functioning at peak performance, filter cartridges should be changed every 6 months. Bunn 39000.1010 UPC 072504095219