The A4 size ribbon cartridge, PC-551, is compatible with many models and allows for long-lasting printing. - Model: PC-551 - Size: A4 size (width 217mm, length 42m) - Compatible models: FAX-105CL, FAX-300CL, FAX-310CL, FAX-320CL, FAX-330DL, FAX-380DL, etc. I had these in stock, but I'm selling them because I no longer have a fax machine and won't be using them.