I want to replace the cells in my electronic filter with a pleated filter. What size filter would I need? Can anyone tell from the specs below?

Manufacturer: Allied Products (division of Carrier Corporation)
Model: 901KAX000016
Product: 901KAX000016AAAA
Serial No.: 0992h03952

The combined dimensions of the two cells inside the unit are:
231/2" deep x 6" w x 181/4" h

Thanks in advance for any ideas on this.